I don't get it. It sometimes is the case that early-stage investors sell off parts of their shares in later rounds, but this is not the norm. In which case yes, there is pressure on later investors to give high late-stage valuations for a company which had high early-stage valuations, but it's not the case that angels and early-stage VC's can ignore the company's final outcome and profit merely by bringing in later stage investors, which is the distinguishing feature of a pyramid scheme.
