It may be tempting, but don't go out and buy a lotto ticket with your tax refund.
If you really want to get the most bang for your buck, follow the advice of legendary investor Warren Buffett and take the "boring" option.
For years, the Berkshire Hathaway chairman has given the same piece of advice to anyone who will listen. "Just put aside a little money every month — put it in a very low-cost index fund," he said in 2015.
Index funds spread your money out over dozens or hundreds of stocks, flattening out the risk while sacrificing the excitement of huge short-term gains and falls.
This "passive" as opposed to "active" investment style of the managed funds, where traders in suits and ties charge large fees trying to pick winners in the market, has proven time and again to be more effective over the long term.