"It was fantastic," she said. "I didn't want it to end. I was sorry that it did."

The Chicago-area resident lost during her 21st appearance, which was on Monday's episode, after accumulating $428,100 in prize money.

Thursday on CNBC's "Halftime Report" Collins, 31, shared her plans for the balance of her winnings after paying off her student loans.

"I went on a fantastic trip to Paris with some of it, but I'm probably going to invest a lot of it and save," she said. "It's a nice nest egg."

Collins asked the traders for investment ideas.

"If you give me any tips on being the next Warren Buffet, that would be great," she said.

Josh Brown of Ritholtz Wealth Management offered some investment tips for the champ.

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"I would suggest having an automated program where you're putting an equal amount of money into the market, every month or every quarter. It costs nothing to set up. That way you don't have to worry about highs and lows," he said. "If you do that over enough time, you're going to win. There's no question about it."

Brown also recommended focusing on midcap stocks "because you have time, you can bear the extra volatility that over 10, 20, 30 years as you approach retirement, will give you the extra gain in your portfolio. So, I would keep it really simple. Keep it automated and structured."

TheStreet's CIO, Stephanie Link, suggested putting some money into actively managed funds.

"And for fun, what I would do, once you have a nice little nest egg, is buy a basket of some really high-growth companies, that—maybe 10 names, like a Google and a Facebook and a Twitter, and certainly a lot of different names like that—and just put it away," she said. "And some will win, and some will lose, but that'll be nice alpha for your portfolio."

Collins, the second-winningest "Jeopardy!" contestant behind Ken Jennings, who won $2.52 million over 74 wins, had words of admiration for her predecessor.

"Having played 21 games, I can't believe it. It takes so much mental stamina and just energy to play that many games," she said. "I can't believe he actually did it."

The trivia clue that ended Collins's streak was: "The New England writer who in 1999 became the last person to win an Oscar for adapting his own novel as a screenplay."

The correct response: "Who is John Irving?"

—By CNBC's Bruno J. Navarro.