The following blog comments originally appeared in a different form on RealMoney and RealMoney Silver on Feb. 19 and Feb. 20.

The

Berkshire Hathaway

(BRK.A) - Get Report

investment debacle continues apace.

Berkshire lost another $500 million in

American Express

(AXP) - Get Report

and

Wells Fargo

(WFC) - Get Report

in the first 15 minutes of trading today, and this came on the heels of losing nearly $350 million in the two names around the lunch hour yesterday.

Moreover, the mark on Berkshire's $30 billion-plus derivative short put trade on the

S&P 500

probably now exceeds $10 billion.

A billion here a billion there, and soon it's real money!

Finally, it is interesting to note that normally non-volatile stocks, such as

Kraft

(KFT)

and

Constellation Energy Group

(CEG)

are under pressure today.

The reason might be that they are large Berkshire Hathaway holdings and short sellers could be smelling blood.

Doug Kass writes daily for

RealMoney Silver

, a premium bundle service from TheStreet.com. For a free trial to

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and exclusive access to Mr. Kass's daily trading diary, please click here.

Know What You Own: Berkshire Hathaway also has a sizable stake in General Electric (GE) - Get Report. For more on the value of knowing what you own, visit

TheStreet.com's

Investing A-to-Z section.When will the downturn end? How can you profit now? Find out at The Traders Expo, a "must-attend" event featuring, among others,

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At the time of publication, Kass and/or his funds were long American Express and Wells Fargo and short Kraft, although holdings can change at any time.

Doug Kass is founder and president of Seabreeze Partners Management, Inc., and the general partner and investment manager of Seabreeze Partners Short LP and Seabreeze Partners Long/Short LP.