I don't trade on traditional markets, so I'm just wondering the following. Take for instance Google stock, right now it's floating around 1000$. I can't imagine the Google stock has the same shitty market depth bitcoin has, e.g. 1000 bitcoins (or 1000 shares) dropping the price by 40$. Why is it that bitcoin has such bad market depth? The price keeps going up but a few big dumps could drop the price back to the low 300's. I can't imagine the same thing happening to Google stock.
Volume. GOOG averages 2,085,000 shares. That's
per day. That means a total transaction value of 2085000 * $1033.56 = $2.155B/day. Bitcoin's total market cap is barely twice that, and its daily volume pales in comparison.
This is a big reason why Bitcoin doesn't behave like a traditional market - it's thinly traded.
The addition of something like the Winklevoss ETF would likely introduce a lot of that traditional market volume into the Bitcoin ecosystem and things would start looking more like Google pretty fast.
Also, Google has metrics like revenue, intellectual property, and so forth that give analysts a reasonable idea of what the company (and thus the stock) is worth. Bitcoin has no clear path to valuation and that means we run on sentiment. We humans are fickle creatures, so running on sentiment alone doesn't do much for price stability.