Editor's Note: This article was originally published on Real Money on Jan. 10. To see Jim Cramer's latest commentary as it's published, sign up for a free trial of Real Money.You aren't supposed to make this money buying low-dollar stocks. Yet, in the last year, you've made a killing if you did so. That's right, if you bought a series of highly visible below-$5 stocks, you made fortunes, and I regard the moves as verification of my theory that everyone should have a speculation in his or her portfolio, because it can keep you in the game by making the process intriguing, and also because you can make huge profits if the story pans out. Specifically, check out these gains. If you bought Sprint Nextel ( S) in May of last year at $2.30, you have now much more than doubled your money. If you had purchased Clearwire ( CLWR) at $0.91 as recently as July 26, 2012, you caught a triple after Sprint bid for the company. Those who had the guts to buy Supervalu ( SVU) -- I know I didn't -- at $1.80 back in October 2012 are verging on a double after the investment made by Cerberus that was announced this morning. And finally, if you had taken a chance with Nokia ( NOK) back in July at $1.69, you have more than doubled your capital after the company announced its sharply better-than-expected earnings today. Frankly, even I, a huge supporter of speculation, am astounded at these gains. Just astounded. How could you not be? In every case, these companies were thought to be on the ropes. Yet it turns out they all had more value than we realized, although the value was obscured, typically, by weak balance sheets. Sprint, Clearwire and Supervalu had been burdened with huge amounts of debt, so much that their solvency was in question when we hit those amazingly low prices. But Softbank took a look at Sprint after it had successfully re-energized its business under super CEO Dan Hesse and liked it enough to buy a huge amount of the company. Clearwire, as tattered as its balance sheet was, turned out to have extremely valuable spectrum, so valuable that even though Sprint decided to buy the rest of it with the money Softbank gave it, Charlie Ergen, a maverick businessman and chairman of Dish Network ( DISH), has been drawn into the bidding for the company, perhaps to get some of that spectrum that is in such short supply and is so needed for additional cell-phone service.