As if it wasn't bad enough reading about the record Christmas bonuses to Wall Street bosses and excessive lifestyles and spending habits of traders and bankers.

Last Friday, the Securities and Exchange Commission issued a new rule on the way the value of stock option packages are calculated.

Under the previous rule adopted in July, companies were required to include the value of unvested stock options in executive pay disclosures beginning in 2007. In other words, they would have been required to come clean on the whole box and dice.

But that was then, this is now.

Under the new rule, sneaked in the Friday before Christmas, companies would only be required to account for the cost of vested options - in plain English, the options an executive can currently exercise - as an expense.

So here's how it works: under the old rule, the entire value of a stock option package worth, say, $25 million over five years would be included in the new compensation documents, and that would happen as soon as it was granted.

Not any more. Under the changes, only about $5 million would be included for each year - and that would depend on how the board structures the vesting schedule, and of course on the share price. Think about that - there's going to be lots in the package that will not be disclosed to shareholders.

As Floyd Norris points out in the New York Times the net effect would be to reduce the information shareholders would get on how much companies are actually paying their executives. Or as Ann Yerger, the executive director of the Council of Institutional Investors told Norris: "It was a holiday present to corporate America".

SEC chairman Christopher Cox has defended the change as a "relative technicality", but as Broc Romanek from TheCorporateCounsel.net says, the well-timed change has a "hint of Festivus".

Just another Christmas present for the big end of town. Or as congressman Barney Frank, who will head the Financial Services Committee told the Washington Post:

"I didn't even know they had a chimney at the SEC, and then all of a sudden this came slipping down it."