Fatwa: Is Day Trading stocks and shares gambling?

Assalamu alaikum,

So if we purchase a share on Monday, are we allowed to sell that on Wednesday or would it be Thursday? I’m not sure if there is a way to know exactly what time settlement occurs - from what I read it’s usually 2 business days.

Also, if one did not wait until settlement in the past, does one have to purify those earnings?

JazakAllah khair