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
Taking into account that most people use Bitcoin as a financial instrument due to how speculative it can be, we can come to the conclusion that a big part of the money comes from Investors. Everyone is buying and puring fiat into BTC to sell later at a profit.