Looks properly rusted for a trade item but doesn’t resemble any arrowhead forms I’m aware of, I’d lean towards a knife too, but if it’s na made from trade metal it really could come in any shape the maker found convenient.
Wouldn't a regular knife have a straighter line on one side of the end ? The 2 sides seem to be pretty equally shaped to me . That's what made me think maybe a trade point, as it has more of a spearhead type end to it rather than a standard knife blade. I dunno just a guess.