Bitcoin is on the rise today, and the reason many are pointing to is an interesting one.Peter Thiel is an American entrepreneur, venture capitalist, author, one of the early investors in Facebook, as well as a PayPal co-founder - and he's spending big on Bitcoin.Today, the Wall Street Journal published a report stating Theil has "amassed hundreds of millions of dollars" worth of Bitcoin, citing unnamed inside sources.This is important for two reasons - first, many investors just follow Theil's lead. In other words, when it's reported that he has invested, that's all they need to hear to do it too.Secondly, it shows a shifting of priorities for a Silicon Valley venture capitalist to be putting money into anything but a start up - many thought cryptocurrencies weren't really on their radar until now.The report brought a spike up today in Bitcoin's valye by over 13% - even triggering mandatory halts in the trading of Bitcoin futures by CBOE.Peter Thiel earlier this year warned that people were "Underestimating" Bitcoin. Looks like he put his money where his mouth is.