After yesterday's impressive recovery, the stock market kept plowing forward Wednesday, with major-market benchmarks gaining 1% or more on the strength of general optimism about how the first-quarter earnings season is going and the overall direction of the U.S. economy. Yet even with those sizable advances, Icahn Enterprises (NASDAQ:IEP), ExOne (NASDAQ:XONE), and Interactive Brokers (NASDAQ:IBKR) managed to give shareholders even more of a good thing, with outsized gains tied to favorable conditions for those companies and their respective industries.

Carl Icahn. Source: Twitter.

Icahn Enterprises jumped 8% after an article in Barron's yesterday afternoon praised Carl Icahn's public investment vehicle, arguing that after nearly a 40% decline in the limited partnership's unit price since late last year, it makes a much more reasonable play for value investors. Although Icahn Enterprises still likely trades above the value of the investments it holds minus its debt, Barron's thinks that the limited partnership deserves a premium to that value based on Icahn's reputation and ability to move markets with his calls. For those who disagree, Icahn's moves are usually so well-choreographed in the public eye that you might be able to get similar exposure simply by owning the stocks that the partnership holds.

ExOne rose 11% on a good day for stocks in the 3-D printing space generally. Despite the lack of any specific news tied to ExOne, the fact that one of its 3-D printing rivals was able to follow through on a secondary stock offering raised sentiment about the prospects of the space for investors. Nevertheless, it's important to remember that even with today's gains, ExOne has plunged about 60% from its January highs, and there are still real questions about whether the fledgling 3-D printing specialist will be able to hold its own in an increasingly competitive market.

Interactive Brokers climbed 12% in the aftermath of its first-quarter earnings report. The discount broker reported huge gains from its year-ago quarter, as revenue soared 64% as adjusted earnings per share more than doubled. In particular, the favorable market helped lift Interactive Brokers' electronic-brokerage segment metrics, as the number of customer accounts grew by 16% and total customer equity jumped 38% on growth in the size of typical accounts. High margin-borrowing levels pushed net interest income up 23% from the year-ago quarter, and Interactive Brokers' market-making segment reversed a year ago loss with a pre-tax profit. As long as the market behaves itself, Interactive Brokers appears to be turning the corner and could deliver greater returns for investors in the future.