Paper Trading vs Live Trading: When Are You Ready?

What Paper Trading Actually Is

Paper trading is simulated trading that uses real-time market data but executes orders in a virtual environment. No actual money changes hands. You see real prices, real spreads, and real market movements -- but every trade is executed against a simulated account balance.

Interactive Brokers provides one of the best paper trading environments available to retail traders. When you open an IBKR account, you automatically receive a separate paper trading account. It mirrors the live platform: same market data feeds, same order types, same charting tools. The only difference is that orders are filled by a simulator rather than routed to a real exchange.

Technically, IBKR's paper environment runs on port 7497, while live trading uses port 7496. slmaj defaults to paper mode on every fresh installation. The setup wizard writes mode: paper and port: 7497 into your config file automatically. You cannot accidentally start live trading without deliberately changing these values.

Paper trading is not backtesting. Backtesting replays historical data and tells you what would have happened. Paper trading runs forward in real time against live market conditions. It is the closest approximation of live trading that exists without financial exposure.

Five Key Differences Between Paper and Live

Paper trading and live trading share the same market data, the same signals, and the same risk logic. But the execution environment introduces differences that every trader should understand before going live.

1. Order fills. In paper mode, orders fill instantly at the displayed price. In live trading, your order enters an actual order book and competes with other participants. Market orders may fill at a slightly different price. Limit orders may not fill at all if the market moves away.

2. Slippage. Slippage is the difference between the expected price and the actual fill price. In paper mode, slippage is zero. In live trading, expect 0.01-0.05% on liquid large-caps (AAPL, NVDA, SPY) and up to 0.5% on less liquid instruments or during high volatility.

3. Market impact. Paper orders do not interact with the real market. In live trading, large orders can move the price against you. For typical slmaj position sizes ($1,000 to $25,000 on liquid instruments), market impact is negligible.

4. Emotions. Watching a paper position drop $200 feels like a data point. Watching a live position drop $200 feels like losing money -- because you are. Many traders who are disciplined in paper mode start overriding their system live: closing winners too early, holding losers too long, or shutting off the bot during a drawdown.

5. Commission timing. Paper mode simulates commissions, but the timing and exact amounts may not perfectly match IBKR's live commission structure, which depends on order routing, volume, and account tier. The difference is small per trade but compounds over hundreds of trades.

Factor	Paper	Live
Order fills	Instant at quoted price	Depends on liquidity and order book depth
Slippage	Zero	0.01-0.5% depending on volatility
Market impact	None	Possible for large orders on illiquid instruments
Emotions	Absent -- no real money at risk	Fear and greed influence decisions
Commissions	Simplified model	Exact IBKR rates based on routing and volume

Why Paper Results Are Better Than Live

Paper results are systematically better than live results. The performance gap typically falls in the 10-20% range. If your paper account shows a +15% return over a month, expect somewhere between +5% and +12% under similar live conditions. That is not a flaw in the paper environment -- it is the natural cost of real-world execution friction.

Slippage and fill quality account for the majority of the difference. Every time a live order fills at a slightly worse price than paper assumed, a small amount of profit erodes. Over hundreds of trades, these small differences compound.

The gap widens with illiquid instruments, larger position sizes, higher trade frequency, and volatile markets (earnings, FOMC days). The gap narrows with liquid large-caps (AAPL, NVDA, SPY), smaller position sizes under $10,000, and lower trade frequency.

The practical takeaway: if your paper performance is barely breakeven, live trading will likely be unprofitable after accounting for these frictions. You want a comfortable margin of profitability in paper mode before considering the switch.

How to Evaluate Your Paper Performance

Raw P&L is the number everyone looks at first. It matters, but it does not tell the whole story. Track these six metrics for a complete picture.

Win rate (% of trades profitable). Above 50% is decent, above 55% is strong. But win rate alone is misleading -- a 40% win rate is still profitable if average wins are much larger than average losses.

Average P&L per trade. The mean profit or loss across all closed trades. This must be positive. If your average paper trade makes only $5, it will likely be negative live after execution costs.

Maximum drawdown (worst peak-to-trough). The largest decline from a high point to a subsequent low in account equity. This is arguably the most important metric -- it tells you the worst pain you need to tolerate. Whatever your paper drawdown was, expect it to be somewhat larger live.

Sharpe ratio (risk-adjusted returns). Measures return relative to volatility. Above 0.5 suggests a modest edge. Above 1.0 is solid. Above 1.5 is strong. Below 0.5 means returns are not compensating for risk. The slmaj dashboard calculates this automatically.

Profit factor (gross profit / gross loss). Total gains divided by total losses. Above 1.2 is acceptable, above 1.5 is good. Below 1.0 means the strategy is losing money and is not ready for live trading.

Number of trades (sample size). With 10 trades, your statistics are meaningless. At 50+, you have a reasonable basis for evaluation. Do not make the go-live decision on fewer than 50 paper trades.

Metric	Minimum for Go-Live	Strong Performance
Win rate	Above 45%	Above 55%
Average P&L per trade	Positive after fees	2x average loss or more
Max drawdown	Within your personal tolerance	Below 10%
Sharpe ratio	Above 0.5	Above 1.5
Profit factor	Above 1.2	Above 1.5
Number of trades	50+	100+

The Go-Live Checklist

Going from paper to live is not something to rush. Use this checklist to evaluate your readiness. If you cannot check every item, continue paper trading -- there is no cost to taking more time.

1. Paper traded for at least 2-4 weeks. This gives you exposure to different market conditions -- trending days, choppy days, news-driven volatility. A few good days in a row is not enough evidence that the strategy works.
2. Completed 50+ trades. You need a statistically meaningful sample size. Fewer than 50 trades is too small to distinguish skill from luck.
3. Sharpe ratio above 0.5. This is a minimum threshold indicating the strategy's returns are at least modestly compensating for the risk taken. If your Sharpe is below 0.5, the edge may not survive real-world execution costs.
4. Max drawdown within your tolerance. Look at the worst drawdown during paper testing. Now imagine that happening with real money -- and potentially being 20% worse than paper showed. Can you accept that without panicking? If not, either adjust your risk parameters or continue paper testing.
5. Understand every risk parameter in your config. Open your config.yaml and explain what each setting under the risk: section does. If you cannot, read the risk controls documentation before going live.
6. Set a personal loss limit you can afford. Decide in advance: what is the maximum dollar amount you are willing to lose before stopping entirely? Write it down. If the bot reaches that limit, you stop. This number should be money you can lose without affecting your financial stability.
7. Reviewed your trade journal for patterns. Look at losing trades specifically. Were stop losses triggered correctly? Did risk controls behave as expected? Are losses concentrated in a particular asset class or time of day? Patterns in the journal can reveal adjustments to make before going live.
8. IBKR live account funded and API enabled. Ensure your live IBKR account is funded, API connections are enabled, and the live trading port (7496) is configured in TWS or IB Gateway. Follow the IBKR setup guide for step-by-step instructions.

See the paper trading guide for detailed instructions on switching from paper to live mode, and the risk controls documentation for a full reference of every configurable parameter.

Your First Week Live

Your first week of live trading should be conservative and closely monitored. The goal is not to maximize profit -- it is to verify that live execution matches your paper expectations.

Start with reduced position sizes. Even if paper testing used $10,000 positions, start live at 25-50% of that. Scale up only after confirming that live fills match your paper results.

# Conservative first-week live config
risk:
  max_position_size: 5000   # 50% of paper test size
  max_positions: 3           # Fewer concurrent positions
  daily_loss_limit: 1000     # Tighter daily cap
  stop_loss_pct: 0.02
  take_profit_pct: 0.04

Monitor actively for the first two days. Watch the dashboard and logs during market hours. Verify that orders fill at expected prices, slippage is within the 0.01-0.05% range, and all risk controls function correctly.

Do not change settings mid-day. Write down adjustments and make them after market close. Changing config values while the bot is actively trading can lead to unexpected behavior.

Keep paper running in parallel. If you can run two TWS instances (one paper, one live), run both simultaneously with the same config. This gives you a direct side-by-side comparison and reveals your real execution gap.

Set a strict daily loss limit. Tighten it to half of your paper-tested value for the first week. After confirming performance is in line with expectations, relax it back to your tested level.

Common Mistakes When Going Live

Most of these mistakes come from impatience or overconfidence after a good paper run.

• Starting with full position sizes immediately. Paper trading gave you a buffer of unreality -- losses did not hurt. Start live at 25-50% of your paper sizes and scale up gradually.
• Going live after only one week of paper. One week is not enough data. You may have traded during a favorable regime and mistaken good conditions for a good strategy.
• Ignoring the paper-to-live performance gap. If paper returned +8% in a month, expect +5-7% live. Plan for the reduced figure, not the paper figure.
• Not having a personal risk budget. Define the maximum dollar amount you are prepared to lose before you start. It should not affect your rent, bills, or financial safety.
• Overriding the bot's signals manually. Closing positions early because of a news headline or holding losers because you "feel" they will recover means you are no longer running the tested strategy. If you disagree with the bot's behavior, adjust the config and retest in paper mode.

Frequently Asked Questions