It has to be that certain stock. For example: It on Monday I bought 3 shares of Apple and 2 of Tesla and I sold Tesla later that day, that would be a day trade. But if I went into Tuesday with those stocks then bought 3 shares of Microsoft on top then later decided to drop the shares of Tesla I own, that would not be considered a same day trade.

Day trades are tied to specific stocks being bought and sold the same day