It's all about the MARGINAL money flow. The question about who's buying isn't important... The important one is, who would be left selling? Who wouldn't have already sold (or gone short) in Aug, Sep, or the first weekend in Oct? Who was left to sell more the last two weeks? I definitely thought the market had room to drop in mid Aug after the first rally.... There were still a lot of vulnerable longs trapped in the market. But now? Half the managers I follow swore they would be cutting net exposure in their portfolios in their Oct investor letter... See John Paulson. Who's left to sell after that? Now in contrast, a lot of these guys need to increase their exposure again. Im not sure the market soars here, but I bet the dips get bought.