The core driving force behind this round of gains is the nearly $50 billion injected into the U.S. stock market over the past week by systematic strategy funds (CTA), hedge funds, high-frequency funds, and leveraged ETFs. These are funds that "care more about price than value."

Their impact is not just pushing the index up a bit, but directly changing the market's operating mechanism: index rises → triggers trend-following models → passive buying → volatility declines → leveraged funds further increase positions → shorts are forced to cover.

First, volatility is declining. The lower the volatility, the more room CTA and leveraged funds have to add positions. In other words, the decline in volatility itself is the amplifier of this rally.

Second, short covering is becoming an important source of marginal buying. That is to say, much of the current buying is not because new longs are particularly optimistic, but because shorts are forced to buy back.

Therefore, the current rally is essentially more like a "liquidity + positioning" positive feedback loop, rather than a broad revaluation driven by a simultaneous significant upward revision in earnings expectations.