Image source: Getty Images Most Canadians use their Tax-Free Savings Account (TFSA) as a cash account. That’s tragic, because cash earns limited interest while the TFSA allows you to mitigate income and capital gains. In other words, why earn 2% a year when you can bet on high-growth tech stocks or exotic assets that deliver triple-digit gains? Here are my top three picks for exotic assets you can hold in your TFSA to create substantial wealth tax-free. Bitcoin To be clear, you can’t hold Bitcoin in your TFSA directly. However, the recently launched Bitcoin exchange-traded fund (ETF) qualifies for TFSA.