JPMorgan Chase (JPM), Wells Fargo (WFC) and Morgan Stanley (MS) kick off big bank earnings on Friday. Bob Lang says the group has ways to go after falling below the 200-Day SMA. He notes signs of a technical bounce but believes a "world of uncertainty" will generate headwinds. Kenneth Leon says "we still like the group" but expects analysts to be conservative and look toward loan growth and reserves as key outlook points.