Here's a scenario that plays out constantly for wheel strategy traders: the stock drops after assignment, your broker shows a loss, you second-guess your decision, and you sell the shares at what looks like a loss. Then you look at your options premium history and realize you were actually profitable the whole time. The problem wasn't your trade — it was the number you were looking at.
Adjusted Cost Basis is the number your broker doesn't show you. It's the one that actually matters.
What Is the Definition of Adjusted Cost Basis in Options Trading?
Adjusted Cost Basis (ACB) is your true effective cost per share of a stock position, calculated after subtracting all option premiums collected from that position over time.
ACB per Share = (Total Share Purchase Cost − Total Net Premiums Collected) ÷ Number of Shares Held
How Does ACB Differ From What Your Broker Shows?
| What Your Broker Tracks | What ACB Tracks |
|---|---|
| Share purchase price only | Purchase price minus ALL premiums collected |
| CSP premiums? ❌ Ignored | CSP premiums ✅ Subtracted from cost |
| Covered call premiums? ❌ Ignored | CC premiums ✅ Subtracted from cost |
| Roll credits? ❌ Separate trades | Roll credits ✅ Included in premium total |
| Dividends? ❌ Separate income | Dividends ✅ Optionally included for performance |
Why Does ACB Matter So Much for the Wheel Strategy?
Without tracking your ACB, you have no accurate way to know whether your position is profitable. Brokers aren't wrong for reporting the share purchase price — that's what they're designed to track. But it creates a systematic blind spot for wheel traders where the most important piece of the picture (all your premium income) is invisible at the position level.
Understanding ACB is what separates wheel traders who think they lost money on an assignment from wheel traders who know they came out ahead. Read the complete ACB calculation guide with worked examples in our step-by-step ACB tutorial.
How Do You Track ACB Without Doing It Manually?
OptionWheelTracker recalculates your ACB after every trade entry — CSPs, covered calls, assignments, rolls, dividends, and fees — automatically. There are no formulas to maintain, no spreadsheet errors to track down, and no gap between what you see and what your actual cost basis is. Your dashboard shows the true number, updated in real time, at every step of your campaign.