Comment by YZF

Correct. The price of the market is the price people are willing to pay. It is not directly related to the move of capital. That said prices are also a function of supply and demand, if there is no demand (e.g.) for US stocks then it is more likely price will go down. If everyone wants to sell US and buy Europe, e.g. because they think the European competitors to Apple, Google, Amazon, nVidia and such will outperform, then presumably the prices at which those companies trade will trend down.