Rumors a few weeks back had Nymex being bought by NYSE Group, dependent on if the CBOE and CBOT deal goes through. Shareholders of the merger are unlikely to vote down the merger, which leaves Nymex the only significant player in that niche, and with the continued wave of consolidation, and John Thane's penchant for trying to be on the cutting edge of electronic markets, it looks like the NYSE rumors are likely to be true.
However, the deal could still fall through, and while the share price has priced in some sort of likelihood of the deal (and thus has some downside risk), the risk/return of the investment is asymmetrical, and can potentially offer a very nice return in the short run.