I've been trading stocks for many years and never found software that could clearly calculate "multiple positions," so I simply wrote one myself.

Recently, while reviewing my trades, my mindset almost broke again.

I mainly do day trading (T), but the brokerage app always lumps all buy records into a single "weighted average cost." This leads to a serious logical problem: even though the trade I sold today was profitable, the system, because the historical holding cost is averaged out, makes it impossible for me to see exactly how much I made on that single trade, and I can't even tell which specific lot I should be selling.

To solve this problem, I recently spent some time writing a small tool. The logic is simple: manage each purchase of the same stock as an independent object.

After trying it for a few days, several features have indeed saved me a lot of trouble:

Multiple Independent Calculations: Each purchase has its own cost and rate of return. When selling, I directly select the specific position, and the profit is clear at a glance, no need to calculate that messy average cost.

Counter-T Reminder: Records the high points of historical sales and gives a reminder when the stock price falls back, saving me from always missing the best position to buy back.

Profit-taking/Averaging-down Aggregation: The system automatically filters out records with the highest return or the most severe losses on a per-stock basis, forcing me to look at data when making decisions, not just go by feel.

This is essentially my personal "little trading review notebook." The current review interface looks like this (as shown in the image), and it's indeed much cleaner than keeping accounts in Excel before.

I'd like to ask the experts in the circle: when you do day trading (T), for managing multiple buy positions, what logic do you generally use to prioritize which ones to sell first? Do you sell the profitable ones first or the ones held the longest?$SpaceX(SPCX.US)