Stocks to watch on Friday:Yelp (YELP) - the consumer review site remains far too cheap for up to 10% annual revenue growth. In addition, Google (GOOG) needs them to survive and thrive to show the government the tech giant doesn't crush competition. Yelp is too cheap with an EV of $2.5 billion and revenues topping $1.0 billion. The stock is in no mans land here at $37. Buy on weakness down back at the lows or on a breakout above $40. CannTrust (CTST) - another day, more bad news. Stay away from the Canadian cannabis company until the HC audit is done and business is restored to normal. Otherwise, the downside risk is $0. Uber (UBER) - the rideshare company reported a $600 million EBITDA loss and faces massive competition in all of their top markets. Avoid the stock.Disclosure: Long YELP