Hedge-fund D.E. Shaw & Co. LP late Monday revealed a 5.1% stake in online-review site Yelp Inc. YELP, +0.02% A Securities and Exchange Commission filing showed that D.E. Shaw has accumulated 4.1 million shares, in what amounts to a passive stake in the company. Yelp's shares have climbed 10.7% so far in 2018, outperforming the market, with the S&P 500 index SPX, +0.74% up 2.2%, the Dow Jones Industrial Average DJIA, +1.21% gaining 1.2% over the same period and the technology-laden Nasdaq Composite Index COMP, +0.54% advancing by 7.1% thus far this year, according to FactSet data. Yelp shares weren't moving in after-hours trade Monday, after finishing the regular session flat on the day at $46.45.