以前说过，北美市场 is a game of MMs and MoMos,

MM 指机构，MoMo 指短期追涨杀跌的traders.

"MM controls direction, MoMos add spike and waterfall."

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one thing that is different from early Chinese stock market is that, for bigger stock, say market cap >1B, often there are many MMs, not just one who sitting in the dark room trying to scalp from small investors, which essentially render trading into a "zero-sum" game, (for small/tiny cap it's often still the case.)

many of mutual funds, by charter, are long only investment funds, they can only look for fundamentals and trying to seek and edge from there. The primary evaluation tool for them is DCF, discounted cash flow.
Some more conservative, some more aggressive, putting more weight on growth rate in revenue, earning, and margins. For example, Fidelity funds, etc.

a lot of hedge funds are free to do whatever they see right, and often they take the short side either due FA or TA reasons, and some do try to control stocks at certain point, legally or illegally. But they also take long side, and often more aggressive than mutual fund peers.

(some ETF are starting to have a greater influence, for example, Pro Ultra Long or Short, or even FXI with its very concentrated holdings. But in generally they have not come to a point to warrant serious considerations. )

so, knows your friends and foos, :), and good luck everyone,