What is a good Sharpe ratio for day trading? (Honest answer, with thresholds)
Sharpe ratio compares your returns to your volatility. For day trading, the thresholds are different than for buy-and-hold investing. Here's what's realistic, what's elite, and what's probably a sample-size artifact.
Sharpe ratio is the standard risk-adjusted return metric. The simple version: Sharpe = (average return - risk-free rate) / standard deviation of returns. The higher, the better — you're getting more return per unit of volatility you took on.
What "good" means depends entirely on the time frame and the strategy. Day traders see different Sharpe numbers than buy-and-hold investors. Here's the honest breakdown for active day trading.
Sharpe ratio for day trading vs investing
Buy-and-hold investing literature talks about Sharpe ratios in the 0.3-0.7 range as normal. S&P 500 long-term Sharpe is roughly 0.4. Warren Buffett's lifetime Sharpe is about 0.8. Hedge fund "good" is 1.0.
Day trading is different because you're not compounding through volatility the same way. Your daily P&L distribution has lower volatility than a buy-and-hold portfolio's daily mark-to-market because you flatten at the end of each day. As a result, day traders see higher Sharpe ratios — sometimes much higher.
Threshold values for day trading
- Below 0.5: marginal. Your day-to-day P&L is too volatile relative to your average. Either size down, reduce position count, or tighten your stop discipline.
- 0.5 to 1.0: profitable but inconsistent. You make money on average, but Friday's win can be wiped by Monday's loss. Most retail day traders sit here.
- 1.0 to 2.0: solid risk-adjusted edge. Your good days outsize your bad days enough that volatility doesn't kill you.
- 2.0 to 3.0: excellent. Top tier of consistently profitable retail day traders.
- 3.0 to 4.0: rare. Verify with 100+ trading days. Often a sample-size effect that collapses to 1.8 once you have more data.
- Above 4.0: skeptical. You're either gaming the math (taking 1 trade a day with a tight stop) or you have a real anomaly. Don't blow up your account leveraging based on this number.
How to compute it on your own data
If you have daily P&L for the last 60+ trading days, you can compute Sharpe directly:
- Compute the mean of your daily P&L (over the window).
- Compute the standard deviation of your daily P&L (over the same window).
- Sharpe (daily) = mean / standard deviation. Note: the risk-free-rate adjustment is usually negligible at this time scale; you can skip it.
- To annualize: multiply daily Sharpe by sqrt(252) — about 15.87. So a daily Sharpe of 0.1 annualizes to 1.59.
Common mistakes
- Computing Sharpe per trade, not per day. Day traders should aggregate to days. Per-trade Sharpe is meaningless because trade frequency varies.
- Ignoring sample size. A 3.5 Sharpe over 20 days is meaningless. The 95% confidence interval is roughly ±1.5 with that few samples.
- Comparing to investor thresholds. Day-trading Sharpe should always be discussed in day-trading context, not investing context.
How TradeFlow Quantum computes it
Sharpe is shown as a headline KPI tile on the dashboard, computed over your last 60 trading days by default (configurable in /settings). The /analytics surface also shows rolling Sharpe (30-day, 60-day, 90-day) so you can see whether your risk-adjusted edge is improving or degrading.