More like, if the market continues the upward trajectory it had under Obama, he gets the credit for establishing that trend. If Trump does something stupid to upset that trend (ill advised tax cuts or tariffs, for instance) he gets the blame. He'd get the credit if he meaningfully accelerated the growth we saw under Obama, but outside of a short bump after the tax cuts that saw a predictable correction shortly thereafter, he hasnt.

It's worth noting I do blame Obama era policies for wage and working condition stagnation/deterioration, which is the thing I actually care about (gdp and unemployment numbers are basically pointless if people who have jobs are living in third world conditions). That said, I have zero hope that the current administrations policies will reverse that trend in any way.

The market went flat the year after Obama's big tax increase.

The market started rising promptly after Trump's election, presumably in anticipation of the coming tax cut.