What you will learn
- Break-even movement
- Cost relative to stop distance
- Effect of turnover
- When costs invalidate a small apparent edge
Break-even movement
Break-even movement must cover relevant costs. For a hypothetical multiplier of ten and fixed round-trip costs of 5 per contract, a favorable 0.50 price move only covers those costs before any additional slippage or financing.
Cost relative to stop distance
Compare total cost with the planned stop distance and expected gross movement. A strategy targeting very small moves can be particularly sensitive to costs. A low advertised spread alone does not establish that the strategy is executable.
Effect of turnover
Turnover multiplies repeated costs. If an account takes many trades, small per-trade fees can become a substantial drag. Evaluate net expectancy using the same assumptions across all trades instead of presenting a gross edge and adding costs as an afterthought.
When costs invalidate a small apparent edge
An apparent positive result can disappear under realistic costs. Rejection is a useful research outcome: it prevents an economically weak idea from being promoted because its chart entries looked attractive. Test uncertainty in costs rather than choosing the cheapest observed period.
Worked example
A hypothetical strategy averages 4 gross per trade over 100 trades. If costs average 5, net expectancy is −1 and aggregate net P&L is −100 before any unmodeled charges. A positive gross average is not sufficient.
Try it yourself
Calculate net expectancy when gross average is 7 and costs are 3, then repeat when stressed costs are 8. Explain what the comparison contributes to a decision.
Show the worked solution
The two net averages are 4 and −1. The strategy is cost-sensitive; the comparison shows why implementation conditions matter. It does not establish how often either cost regime will occur.
Apply this to your course project
Compare two hypothetical trade statements and explain their different net outcomes.
Keep the calculation inputs, assumptions and decisions with your work. Practical exercises are self-reviewed; the scored knowledge checks assess the questions shown, not an independent certification of practical competence.