The only chance of Bitcoin dropping to $10 is if an early investor tosses 2-4 million coins on the market all at once.
I think a dump of 100,000 bitcoin on bitstamp would bring the price to $10. However whoever did that would be throwing away 80% of their wealth for no reason, the price would again recover very quickly.
100k bitcoins alone cant do a shit. Someone doing that after some bad news, could maybe pull price till 100 USD for a day. But reality is, that BitCoin will just get tons of good news.
Yap 100k might drop price a bit but no way anybody would sell that low so price cant go down to much. And if u dump them all on lets say bitstamp it will only crash that exchange.
It will take much much more to crash bitcoin than 100k coins.