TheStreet's Jim Cramer is concerned about Twitter's stock lockup expiration this week but he says Twitter's deal with Amazon is a step in the right direction. Cramer also thinks JPMorgan's warning that trading revenue could drop 20% is a little extreme and despite the downgrade, he thinks JPMorgan, Goldman Sachs, and other banks can come back. Finally, Cramer says he is disappointed in Linn Energy's quarter and he warns investors to watch distribution growth in oil and natural gas producers.