A TFSA can save you a massive amount of cash, especially if your investment hits a huge home run. Here’s how you can use it to prosper. The TFSA (Tax-Free Savings Account) is where I put stocks that are expected to have the most enduring and highest returns. Simply, I don’t want to pay any tax on a significantly compounded gain. How much tax could the TFSA save you? Say 15 years ago, you had invested $10,000 in Constellation Software (TSX:CSU). You would have been able to buy 234 shares at a price of $42.72 per share. If you held to today, your shares would be worth $1,142,622. If you needed to sell, you would be sitting with a capital gain worth $1,132,622. Depending on where you live, you could be liable for a tax bill for as much as $283,000. Subtract that tax from your return and you would only be left with $859,466. The point being that tax matters when you are investing. That is especially true if you hope to earn a big gain one day. That is why the TFSA is literally a priceless tool for Canadian investors. If you held your Constellation shares in a TFSA, you would have paid no tax and been $283,000 richer. It will be hard to find stocks that will replicate the 124,000% return that Constellation delivered since 2010. However, even half or a quarter of that return would still work out very nicely for a TFSA investor. If you are looking for stocks that could have some big gains, here are three to consider if you have $10,000. A stock for a long-term TFSA portfolio Recent performance at Trisura Group (TSX:TSU) has been somewhat lacklustre. However, its longer-term returns have been very attractive. Its stock is up 287% in the past five years and 625% since it was spun-out in 2017. It provides specialty and fronting insurance solutions in the U.S. and Canada. The past few years have been building years for this company. The custom insurance provider should be set to reap some of those investments into staff and infrastructure. The company has a consistently strong return on equity ratio and a low operating ratio. Today, this TFSA stock trades at a book value per share far below its average range. A mini-Constellation Software Topicus.com (TSXV:TOI) is like a mini- Constellation Software. It is completing a very similar mission by consolidating relatively small niche software companies in the European market. Topicus has a lot of qualities to like in a long-term compounding stock. It has a highly invested management team, a strong balance sheet, a large market to consolidate, and a high rate of reinvestment. Topicus is a great stock to hold if you want diversification out of North America. TOI is not a cheap stock today after running up 26% this year. However, if it takes a dip on any market pullback, it would be a great addition to a TFSA portfolio. A long-term compounder to hold Another stock with a long growth runway ahead is Colliers International Group (TSX:CIGI). The company has delivered high teens returns over the two decades. Yet, its stock is down 17% in 2025. Colliers has been a very strategic acquirer of real estate services providers around the world. It now has strong brands and presence as a commercial broker, property manager, engineering/advisory, and investment management. This commercial realtor’s business is much more resilient and consistent today than ever. The company has a highly invested management team. Its platforms continue to steadily grow. CIGI a nice stock to tuck away for the long run inside of a TFSA.