UBS analyst Brennan Hawken downgraded Charles Schwab to Sell and lowered his price target for the shares to $42 from $48. The analyst sees revenue headwinds at the same time as risk to upward pressure on expenses. This will lead to earnings and multiple compression, Hawken tells investors in a research note. The analyst believes Schwab's revenue guidance, which assumes a mid-year rate hike and higher daily average revenue trades, is aggressive against the current backdrop. Expectations may be too high and could put the stock at risk, particularly since buybacks are likely not enough to "cushion the blow to the growth story," Hawken contends.