How to understand the calculation of my profit in Binance?

So, if I have 0.0001 BTC, i.e., 0.1% BTC, then if my profit is 1$, the BTC price has gone up 1000$, but since when I bought the BTC, the price hasn’t varied for more that +/- 300$, maybe something else goes into the Profit & Loss computation in Binances’ margin page?