The manual entry problem hits derivatives traders hardest. On a perps exchange, a single position might accrue funding payments every 8 hours, have different maker and taker fee rates on entry and exit, and experience slippage that varies by market conditions. Getting all of that into a spreadsheet requires pulling data from your exchange after every trade.
Most traders simplify. They enter the entry price, exit price, and position size — then skip fees, funding, and slippage. The result is a journal that overstates winners and understates losers. Your "55% win rate" might be 48% after real costs.
The second failure mode is skipped trades. After a bad session, opening Google Sheets to document three consecutive losers requires discipline that most people don't have on their worst days. But those are exactly the trades that reveal your leaks — the revenge entries, the oversized positions, the ignored stops.
If you can maintain the discipline, Google Sheets is an excellent journal. If you find yourself skipping entries or estimating fees, consider automating the data capture and spending your energy on the review instead.
