How Sleep, Hormones and Lifestyle Are Affecting Your Trading

Kim Ann Curtin Kim Ann Curtin
June 9, 2026 21 min read

Most trading psychology advice treats the mind as if it operates independently of the body. It doesn’t. Your cortisol level at 9:30am, the quality of your sleep the night before, and whether you exercised this week can all affect how well you make decisions once the market opens. I’m the only trading psychology coach (that I know of) who recommends clients do diagnostic lab panels, 84 biomarkers including the hormones directly implicated in risk tolerance and impulse control. Here is what we know, what we don’t, and what I’ve seen.

Quick-read summary:

  • After a night without sleep, people in one study leaned toward chasing gains and worried less about losses
  • Stress hormones and testosterone move with a trader’s results, and may shift how much risk feels acceptable
  • Thyroid function, vitamin D and inflammation can affect energy, mood and focus
  • I encourage traders to get lab work with their doctor, because sometimes part of the pattern is physical

The Biology Beneath the Psychology

Why trading psychology can’t be separated from physiology

I’ve worked with hundreds of traders and financial professionals over the past 20 years, from institutional environments including firms like Morgan Stanley, Bank of America, King Street Capital, Anchorage, Fortress, GIC and Blackstone, to retail trading communities like Investors Underground, TrueTrader and Bear Bull Traders. One pattern has become increasingly clear: the traders who struggle most with discipline, emotional regulation, and consistency often share underlying biological and nervous system vulnerabilities they don’t even realize are influencing their performance.

Your prefrontal cortex, the part of your brain responsible for executive function, following rules, and maintaining discipline, is easily worn down by stress and poor sleep. When it is, the part of you that reacts before you can think has more say.

This is the same neurological mechanism I described in How to Control Your Emotions While Trading. But here’s what most traders miss: lifestyle factors create the vulnerability before the market opens. You’re not losing discipline because you’re weak. You’re losing it because your nervous system is already compromised when you sit down to trade.

The hormones that matter most for traders

Cortisol: The stress hormone you’re trading with

Cortisol is your body’s primary stress hormone. It’s elevated chronically by poor sleep, overtraining, inflammatory diets, and psychological stress. For traders, cortisol has a paradoxical effect: in some people, high cortisol increases risk aversion. They freeze, can’t pull the trigger, watch setups pass by. In others, it creates recklessness. They overtrade, chase, revenge trade.

The best-known study here is Coates and Herbert (2008), published in PNAS. They took saliva samples from 17 male traders on a London trading floor over eight days, and compared morning hormone levels with each trader’s results that day.

Traders’ stress hormone levels rose when their results swung more widely and when the market was more volatile.
(Coates & Herbert, 2008, PNAS)

It was a small group over a short time, so I hold it lightly. What it tells me is that the body moves with the market. It doesn’t tell us how much of a trader’s results come from that.

Here’s another thing most traders don’t know: cortisol follows a natural daily rhythm. It’s highest in the first 30–45 minutes after you wake, a spike designed to mobilise your body for the day. If you trade the market open, you’re making position-sizing decisions during your daily cortisol peak. That’s not inherently bad, but it means you need to be aware of it. If you slept poorly, if you’re already stressed, that cortisol spike amplifies everything.

Watch: Trading Psychology Podcast: Cortisol’s Impact on Trading, deep dive into how the “flight chemical” disrupts trading performance.

Testosterone: The winner effect

Testosterone increases risk tolerance and confidence. In the same Coates & Herbert study, morning testosterone levels predicted afternoon profitability in male traders. The researchers suggested something more: that a run of wins could push testosterone up, make risk feel more acceptable, and set a trader up for a fall. They didn’t test that directly. It is an idea, and it fits what I see.

They linked it to the “winner effect,” first described in animals. You win, you feel invincible, you get bigger, and then you give it back. I’ve seen this pattern hundreds of times, the trader who has three great days, then blows up on day four. It looks like overconfidence, and the body may be part of it too.

This is the same biological mechanism discussed in Is Trading Really 80% Psychology?, the hormonal factors that influence decision-making often operate beneath conscious awareness.

One important caveat: the Coates study was conducted only with male traders. Female traders have a different hormonal profile, with cycle-related dynamics that affect cortisol, estrogen, and progesterone. This area is dramatically under-researched, and I’m honest about that with my female clients. The biology is real, but the specific research on female traders is sparse.

Thyroid: The invisible performance drain

Subclinical hypothyroidism, low thyroid function that doesn’t meet the diagnostic threshold for disease, can bring fatigue, foggy thinking and low motivation. Some traders put these down to burnout or a lack of discipline when their thyroid may be part of the picture.

Here’s the problem: standard GP blood panels typically test only TSH (thyroid-stimulating hormone). Subclinical issues often show up only when you test Free T3, Free T4, and Reverse T3. I’ve had clients whose TSH was “normal” but whose Free T3 was at the bottom of the reference range. Once they worked on it with their doctor, the “foggy thinking” they’d been putting down to psychology lifted.

Vitamin D: The overlooked cognitive factor

Low vitamin D is linked to depression, low motivation, and cognitive decline. It’s widespread, especially in northern climates and among screen-based workers who spend their days indoors. When it’s low, it’s worth raising with your doctor. I suggest it be included in every panel.

Watch: Cortisol, Dopamine, and Nervous System Overload in Trading, understanding the hidden biological forces behind trading stress.

The Sleep-Trading Performance Connection

What happens to your trading brain after poor sleep

Sleep deprivation reduces prefrontal cortex activity. That’s the same effect as acute psychological stress, the part of your brain responsible for discipline and rule-following goes offline first.

Matthew Walker’s Why We Sleep summarises decades of research: after 17–19 hours without sleep, cognitive impairment is equivalent to 0.05% blood alcohol. You wouldn’t trade drunk. A long day on too little sleep deserves the same respect.

Here’s the part that surprises people: being tired may not make you more careful. Normally a loss hurts more than the same size win feels good. When you’re short on sleep, that can shift.

After one night without sleep, 29 volunteers in a Duke study shifted toward chasing gains and became less bothered by possible losses when choosing between gambles.
(read the study)

That was a full night without sleep, which is more than most traders go through. But in my experience, traders who slept badly also say their setups look less clear and their patience runs out sooner. This is why understanding what makes an elite trader includes recognising the importance of biological preparation.

Watch: Matthew Walker: Sleep Is Your Superpower, TED Talk summarising the cognitive costs of sleep deprivation.

Watch: How Sleep Affects Your Trading Performance, practical analysis of sleep’s impact on trading decisions.

What “good sleep” actually means for a trader

Most traders know sleep matters. But “getting enough sleep” isn’t specific enough.

Quantity: Seven to nine hours for most adults. Under six hours is measurably impairing. This isn’t aspirational. It’s the minimum threshold for cognitive baseline.

Quality: You can sleep eight hours and still wake up foggy if your sleep was broken. Alcohol, even a moderate amount, tends to disturb sleep later in the night, so a glass of wine at 9pm can show up in how you feel the next morning.

Consistency: Irregular sleep schedules disrupt your circadian cortisol rhythm. If you go to bed at 11pm on weekdays and 2am on weekends, your body doesn’t know when to produce cortisol. That directly affects your mental state during morning trading.

Pre-market sleep hygiene:

  • Screen cutoff 60 minutes before bed (or blue-light glasses if that’s not realistic)
  • Room temperature between 65–68°F / 18–20°C, cooler than most people keep their bedrooms
  • No alcohol within three hours of sleep
  • Consistent wake time, even on weekends

For sleep quality tracking: the Oura Ring tracks sleep stages, HRV, and body temperature, particularly useful for identifying when sleep quality degrades even if duration seems adequate.

The early market open problem

The NYSE opens at 9:30am ET, but most serious traders have already been working for hours before the bell, reviewing news flow, mapping levels, analyzing overnight price action, journaling, preparing game plans, and regulating their emotional state for the trading day ahead.

That matters because the issue isn’t simply what time someone trades. It’s whether their nervous system and cognitive wiring are aligned with the demands of high-stakes decision-making during those hours.

Cortisol naturally spikes in the early morning, which can be helpful for alertness and focus, but for some traders, especially night owls fighting their natural chronotype, it can also amplify anxiety, impulsivity, emotional reactivity, or mental fog. In other words, they may be attempting to make elite-level decisions at a time when their brain and body are not naturally operating at their best.

Chronotype matching matters more than most traders realize. I’ve seen traders improve dramatically, not necessarily by trading later, but by restructuring their preparation, sleep timing, morning routine, caffeine use, exercise, and recovery patterns so their cognitive peak better aligned with the demands of the trading session itself.

The setups didn’t suddenly improve. The trader’s brain state did.

For traders, performance is never just about strategy. It’s about whether the nervous system supporting the strategy is regulated, resilient, and biologically capable of sustaining disciplined execution under pressure.

Watch: How to Develop a Sleep Routine to Improve Your Trading Performance, SMB Capital’s practical guide to sleep optimization for traders.

My Diagnostic Lab Panel Approach

Why I added biomarker review to my coaching practice

About five years into my coaching practice, I started noticing a pattern. Some clients were doing the psychological work, journaling, following their plans, implementing the mindfulness practices, but they weren’t moving the needle. The discipline wasn’t sticking. The emotional reactivity wasn’t resolving.

My hypothesis: something upstream was creating the pattern that psychology alone couldn’t touch. So I started recommending comprehensive lab panels. And I found significant correlations.

A client with chronic revenge trading had a cortisol panel showing adrenal dysregulation, his body was producing stress hormones in a pattern consistent with chronic overactivation. We addressed it with a lifestyle intervention alongside the coaching work, and he finally started seeing results.

Another client with decision paralysis and low confidence had low testosterone and a vitamin D deficiency. Once he worked on those with his doctor, the confidence work we’d been doing in coaching actually landed. The mindset shifts started sticking.

What I took from it: sometimes part of a psychological pattern is physical. In my experience, when traders look after both, the coaching tends to stick better. This is why I emphasize this approach when discussing whether a trading psychology coach is worth it, the biological dimension is a differentiator.

What the 84-biomarker panel covers

I’m not a doctor. I don’t prescribe or diagnose. But I am the only trading psychology coach (that I know of) who routinely suggests clients’ do comprehensive blood panels to identify patterns that suggest a biological factor may be contributing to psychological patterns. When I see something, I refer to appropriate practitioners.

The full panel I recommend covers approximately 84 biomarkers. It’s not a standard GP “annual blood test”. It’s a functional medicine panel designed to catch subclinical issues.

What the panel includes:

  • Standard metabolic panel and CBC (baseline)
  • Full thyroid panel: TSH, Free T3, Free T4, Reverse T3, most GPs only test TSH, which misses subclinical hypothyroidism
  • Sex hormones: testosterone (total and free), estradiol, DHEA-S, progesterone
  • Adrenal: cortisol (four-point saliva test preferred over single serum draw for accuracy), DHEA
  • Inflammation markers: CRP, homocysteine, ferritin
  • Nutrients: vitamin D, B12, magnesium, omega-3 index
  • Melatonin (where testable)

Learn more about comprehensive biomarker testing from this PMC research article on blood biomarker profiling for high-performance athletes, some of the same thinking may apply to traders.

What the data reveals that psychology coaching alone misses

One trader shared something with me that completely changed how I think about performance optimization in trading.

He didn’t suddenly increase his position size.
He didn’t start trading exotic products.
He didn’t add more leverage.
And he didn’t overhaul his strategy.

What changed first was his biology.

After comprehensive lab work revealed several underlying hormonal imbalances, he began working on hormone optimization. Not long after, his trading performance shifted dramatically.

He described feeling calmer under pressure. Less reactive. More emotionally steady during volatility. Better able to sit with uncertainty without forcing trades or second-guessing decisions. His energy improved. His sleep improved. His recovery improved. And over time, so did his consistency.

The most fascinating part?

The jump in his portfolio returns began shortly after addressing the physiological issues that had quietly been impairing his cognitive and emotional performance all along.

Too many traders assume every performance problem is psychological, strategic, or discipline-related.
Sometimes the issue is biological.

Hormones influence focus, impulse control, emotional regulation, stress tolerance, sleep quality, recovery, motivation, confidence, and decision-making under pressure, all things traders rely on every single day.

As this trader shared with me:

“I didn’t fully understand the value of having optimized hormones until I saw my portfolio returns dramatically improve. The delicate balance of hormones in the body has a massive impact on my ability to make calm, rational decisions in response to fluctuations in the market. What started with comprehensive blood work ultimately improved not only my trading performance, but also my performance in the gym, my energy, recovery, and overall quality of life.”

For traders, performance optimization isn’t just psychological. As I talk about here: Why Do I Keep Breaking My Trading Rules?
It’s physiological too.

“I saw my portfolio returns jump from 5% to 30%… Kim understands the importance of hormone health.”, PT, Part-Time Trader

This is not about replacing psychology with biology. It’s about recognising that they’re inseparable. If I’m coaching someone on discipline and their cortisol is dysregulated, we’re fighting biology. If I’m coaching someone on confidence and their testosterone is low, the mindset work won’t stick.

How to get a comprehensive panel

You don’t need to work with me to run a lab panel. (Although I do offer that here)

Where to order:

  • Functional medicine doctor, ideal if you want interpretation and follow-up care
  • Direct-to-consumer labs: Ulta Lab Tests, Any Lab Test Now, Marek Health (US-focused)
  • Cost: typically $200–$995 out of pocket; insurance rarely covers full panels

What to ask for specifically:

  • Full thyroid panel (not just TSH)
  • Full sex hormones (testosterone total and free, estradiol, DHEA-S, progesterone if applicable)
  • Cortisol, saliva test preferred over single serum draw for accuracy; four-point cortisol curve is ideal
  • Vitamin D, B12, magnesium
  • CRP (inflammation marker)

When you get your results, look for patterns, not just values outside the reference range. Subclinical issues, values at the low or high end of “normal”, are worth discussing with your doctor, and can sometimes be part of what you’re feeling.

As part of my coaching process, I often encourage traders to look at both the psychological and physiological sides of performance. While I’m not a physician and do not provide medical advice or interpretation of lab work, I do help clients explore how factors like sleep, stress, recovery, hormones, nervous system regulation, and overall health may be impacting their emotional consistency and decision-making in the markets.

If you’re already working with a physician or doing lab testing and want support integrating those insights into your trading performance and emotional resilience, you’re welcome to book a free call and bring any relevant information you’d like to discuss.

You can also learn more about The Wall Street Coach’s broader approach, along with client results and testimonials.

The Lifestyle Protocol for Trading Performance

Sleep protocol

This isn’t aspirational. It’s the minimum baseline for cognitive performance.

  • Consistent sleep/wake schedule, including weekends; irregular schedules disrupt cortisol rhythm
  • Target 7–9 hours, track quality, not just quantity
  • No screens 60 minutes before bed, or use blue-light glasses if that’s not realistic
  • Cool room: 65–68°F / 18–20°C is a commonly recommended range for sleep; many people keep their bedrooms too warm
  • No alcohol within 3 hours of sleep. It suppresses REM, the phase that consolidates decision-making

If you’re serious about trading performance, sleep is non-negotiable. I’ve had clients improve consistency purely by fixing their sleep schedule, no other changes.

Movement and trading performance

Exercise helps your body handle stress and helps you think clearly. Both matter at the desk. This connects to the principles discussed in developing trading discipline, physical preparation supports mental discipline.

Morning exercise specifically: If you trade the market open, morning exercise regulates cortisol and sharpens focus. It doesn’t have to be intense, a 20-minute walk in daylight is enough to shift your nervous system into a regulated state.

Overtraining caveat: Excessive training increases cortisol. If you’re training hard six days a week and your trading performance is declining, check your HRV (heart rate variability). It’s a proxy for nervous system recovery. If HRV stays below your baseline, it may be a sign you need more recovery.

The WHOOP Strap provides continuous HRV and recovery tracking, particularly valuable for traders who need to know their nervous system readiness before market open.

Nutrition and timing

Steady blood sugar helps you stay steady. A big spike and crash can feel a lot like stress: shaky, irritable, impatient. None of that helps at the desk.

Pre-market meal:

  • Protein + fat, low glycemic index
  • Avoid high-carb breakfast before the open, the blood sugar spike and subsequent crash happen during your trading session

Caffeine:

  • Effective for alertness, but it elevates cortisol
  • Optimal timing: 90–120 minutes after waking, not immediately upon rising (let your natural cortisol spike do its job first)

Alcohol:

  • Even moderate intake disrupts sleep architecture
  • One drink at 9pm can still leave you less sharp the next morning

The trader’s 10-minute morning protocol

This is what I recommend. It operationalises the nervous system awareness this article is built on.

  1. HRV check, Use Oura, Whoop, or a similar device. Is today’s HRV reading significantly below your baseline?
  2. Body scan, Am I stressed? Rested? Emotionally regulated? This is mindfulness in its most practical form.
  3. One-sentence intention, What’s my focus for this session?
  4. Decision point, If HRV is well below your baseline, take it as a cue to slow down and settle yourself before you trade.

This isn’t about perfect data. It’s about self-awareness before you’re in the heat of a position. Elite traders, as I wrote in What Makes an Elite Trader?, prepare their nervous system before they prepare their watchlist.

The free Trader Check-In is a structured version of this protocol, a five-minute pre-market emotional and psychological state assessment. This same approach applies whether you’re preparing for a prop firm challenge or your daily trading session.

Watch: 3 Sleep Hacks That Fixed My Trading, practical insights from Matthew Walker’s research applied to trading.

“I just had my best January since I began trading 5 years ago… This has everything to do with trading in peace.”, Karim Abdelkader, Trader

Frequently Asked Questions

Does sleep really affect trading that much?

It can. After 17 to 19 hours awake, people perform on some tests about as badly as they do at 0.05% blood alcohol. In one study, a night without sleep made volunteers more drawn to gains and less bothered by losses. And in my coaching, sleep is one of the first things I ask about when a trader’s discipline slips.

What hormones are most important for trading performance?

Stress hormones and testosterone are the best studied in traders. Both moved with traders’ results in a small study on a London trading floor. Thyroid hormones (T3/T4) affect cognitive baseline, and low thyroid function can feel like “brain fog” that traders put down to psychology. Vitamin D, while not a hormone in the traditional sense, is linked to mood and energy. The research on cortisol and testosterone in financial trading is still early and based on small groups.

How do I get a lab panel to check my biomarkers?

You can order through a functional medicine doctor or direct-to-consumer labs like Ulta Lab Tests, Any Lab Test Now, or Marek Health. Ask specifically for a full thyroid panel (not just TSH), full sex hormones, four-point cortisol (saliva preferred), vitamin D, B12, magnesium, and CRP. Typical cost is $200–$995 out of pocket.

Does Kim review lab panels as part of coaching?

I’m not a physician, and I don’t give medical advice or interpret lab work. I do encourage traders to get comprehensive blood work with their doctor, and if you’re already doing that, you’re welcome to bring what you’ve learned into our sessions. When something suggests a physical factor, I refer to appropriate practitioners. I’m the only trading psychology coach (that I know of) who does this. Learn more about coaching with lab panel review here.

What’s the most important lifestyle change for traders?

Sleep. If you change nothing else, fix your sleep schedule. Consistent 7–9 hours, cool room, no alcohol within three hours of bedtime, no screens an hour before sleep. It’s not glamorous, but it’s the highest-leverage change most traders can make.

The Biological Foundation of Trading Psychology

Most of the psychological patterns traders struggle with, impulsivity, hesitation, revenge trading, rule-breaking, have biological substrates. That doesn’t mean psychology doesn’t matter. It means psychology works better when the biology is stable.

This is the intersection I work in. I’m not a biohacker. I’m not a functional medicine doctor. I’m a trading psychology coach who realised that ignoring the body when coaching the mind was leaving half the picture unaddressed.

If you’ve been working on your trading psychology and the patterns aren’t shifting, consider whether something biological might be creating the vulnerability. Sleep, stress and health can all affect how steady you are under pressure. In my experience, the traders who look after both their mind and their body tend to find the work sticks better.

Similar principles apply when traders experience FOMO in trading or struggle with overtrading, the biological state often precedes the psychological pattern.

The TPI Assessment maps your psychological decision-making profile, and in coaching we can look at sleep, stress and health alongside your trading. For those interested in a deeper approach, explore The Wall Street Coach’s trader coaching programs.

Psychology is only part of the picture. If you want to understand the full system, mind, body, and biology, book a free call with me and bring your lab results. You can also explore my book Transforming Wall Street for deeper insights into this integrated approach.

For ongoing support and insights, listen to The Wall Street Coach Podcast where I explore these topics with leading traders and performance experts. You might also explore AI-assisted trading psychology coaching as a complementary tool.

About the Author

Kim Ann Curtin, known as The Wall Street Coach™, is a trading psychology and performance coach who works at the intersection of decision-making and the nervous system. For over 20 years, she has worked with institutional traders, hedge funds, and senior executives. Her clients include traders and executives affiliated with firms such as GIC, Morgan Stanley, Bank of America, King Street Capital, BC Partners, and Blackstone, along with leading trading communities including Investors Underground, Bear Bull Traders, True Trader, and StocksToTrade. She has also coached traders and leadership teams at CenterPoint Securities. She is the author of Transforming Wall Street and host of The Wall Street Coach Podcast (110+ episodes), focused on helping traders perform at a high level when it matters most. Book a free call with Kim.

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