XOMA (Nasdaq: XOMAD) shares popped 15-fold yesterday, but investors aren't necessarily any richer.

The biotech with a knack for novel antibody therapeutics simply executed a 1-for-15 reverse split, swapping 15 old shares for a single new share at a price point 15 times higher. The share count and the share price have changed, but the underlying value hasn't.

Mr. Market typically scorns reverse splits as a desperate measure, intended either to gain exchange-listing compliance or shake out the fly-by-night speculators who feverishly trade in and out of penny stocks. In Xoma's case, the company's drug pipeline consists mostly of long shots, and even though it has cranked out the occasional quarterly profit, deficits are far more common over the past few years. Xoma's shares also took a 14% hit after executing its reverse yesterday -- not surprising for companies where a reverse split simply delays the inevitable.

However, reverse splits are no longer solely the feeding grounds for fading companies at risk of delisting. E*TRADE (Nasdaq: ETFC) pulled off a 1-for-10 reverse split three months ago, even though the discount broker never broke the buck. A month earlier, Citigroup (NYSE: C) asked shareholders at its annual meeting to give it another year to decide on declaring a reverse split. Investors granted the extension, even though Citigroup has been respectably trading in the mid-single digits for several months.

With these big names making reverse splits seem more respectable in Wall Street's eyes, I wouldn't be surprised to see other prominent companies follow suit. Here are four possibilities I'll be watching for in the coming months.

YRC Worldwide (Nasdaq: YRCW) - $0.27
Trucking giant YRC isn't as small as its share price suggests. This Fortune 500 company raised a good chunk of change earlier this week by selling its global logistics business.  

Despite bankruptcy-filing fears among investors, YRC is doing its part to keep on truckin'. Its flagship business has shown sequential improvement as YRC posts narrower deficits.

This stock traded in the double digits two years ago, but YRC may need a reverse split to maintain listing compliance, assuming it doesn't plan on filing for Chapter 11 reorganization.

Sirius XM Radio (Nasdaq: SIRI) - $1.00
No one's laughing at the satellite-radio provider these days. Sirius XM has delivered four consecutive breakeven quarters, and it's upped its guidance several times this year.

Even though its share price weaves in and out of the $1 mark, the company seems unlikely to go under that threshold long enough to trigger an exchange delisting.

However, Sirius XM may still want to consider a reverse split, because it just has too many shares outstanding. With 6.4 billion -- yes, billion -- shares outstanding as of its latest quarter, the premium radio titan is commanding an enterprise value approaching $10 billion. If it wants to trade at a high enough price point to swap out speculators for institutional investors, a reverse split may do the trick. Otherwise, it'd likely take several years of blowout quarters to even approach the $5 mark.

Evergreen Solar (Nasdaq: ESLR) - $0.65
The skies may not seem all that bright at Evergreen these days. The solar energy specialist has been consistently trading below the buck since May. The low price may add some speculative sizzle to a sector that's never short on zing to begin with, but listing requirements may force Evergreen's hand.

Unlike many of the larger solar players, Evergreen isn't presently profitable. However, at least one analyst thinks that the maker of String Ribbon solar power products will turn profitable by next year.

Vonage (NYSE: VG) - $2.11
The web-based phone service is back. After a rocky IPO and a gradual descent to pocket change, Vonage has rattled off several profitable quarters in a row.

It's in the same camp as Sirius XM on this list. It doesn't need to pull a reverse to gain any kind of exchange compliance, but it may want to declare one -- just so it can whittle down its share count and join its telco and telephony peers at higher price points.

Skype's IPO may draw investing interest in the web-based communications space, and Vonage may as well dress up before the party arrives.