Coinbase is always higher than the rest of the markets for some reason... I think it's because they are incredibly slow in transaction times. Right now it's pretty equal tho, look at current Bitstamp and Coinbase prices.

Different technical analysis depending on the exchange is normal, but this figure is indeed very interesting, that wick is very aggressive and made a symmetrical triangle while Bitstamp is forming an ascending one... hard to say, but im bullish. I don't think Coinbase is a market maker, in fact, no exchange is, at this point Bitcoin is too big, too many markets with solid volume.