The marked cap for BTC have increased from 60 to nearly 120b$ since september. In the meantime, the total market cap (BTC excluded) is somehow stable, only 10b$ have gone out of altcoins in the same period.
Where do you think the money that goes into BTC comes from? Margin trading? New money?
Do you know something by fact and a link that can support it
Margin trading can't create such huge and consistent increase. It's obviously new money coming in. My bet is institutional investors. And it also explains why it's only Bitcoin - because the are going after "blue chips"