Barclays Plc just upended one of the most common narratives for why hedge funds are struggling to repeat the glory years: they found it's not the number of funds that's causing returns to languish. It's their size. That calls into question a piece of wisdom so well received that even the industry itself has started to repeat it. Barclays polled 340 investors with about $8 trillion in assets under management, and 74 percent of them said the primary reason for meager returns is that the industry itself has become too big.