Financial and real estate exchange traded funds (ETFs) have got a real case of the Mondays.

Uncertainty still abounds in the financial sector. Lehman Brothers (LEH) shares dropped midday after speculation about the future of its CEO and the bank’s independence, reports the Associated Press. The Korean Development Bank is rumored to be thinking about making a bid, but the bank’s spokesman declined to comment.

Meanwhile, Lehman’s CEO is facing a campaign to have him give up day-to-day control. Lehman Brothers is the nation’s fourth-largest investment bank and considered to be the most vulnerable to the credit crisis.

AIG’s (AIG) shares dropped to a 13-year low after Credit Suisse forecast a huge loss for the insurer. Currently, Credit Suisse estimates that AIG’s financial products are sitting on a $6.5 billion loss. The brokerage had previously estimated a $2.6 billion loss, report Eric Yep and Jonathan Spicer for Reuters.

One thing that could be hurting the financial ETFs is their small-cap exposure, says John Spence for MarketWatch. The boost that small-caps saw earlier this summer came largely from investors looking to buy low in the beat-up financial sector, but today the enthusiasm is waning.

Existing home sales rose 3.1% last month, which was nearly twice the expected amount, says Alan Zibel for the Associated Press. But the number of unsold homes managed to hit a record high, and prices are still not at their bottom, experts say.

Home sales are off 13% from a year ago, and prices are down 7.1% in the same timeframe.

Affected ETFs:

• Financial Select Sector SPDR (XLF), down 27.1% year-to-date
• Regional Bank HOLDRs (RKH), down 23.1% year-to-date
• iShares Dow Jones Broker-Dealers (IAI), down 35.8% year-to-date
• DJ Wilshire REIT (RWR), up 0.9% year-to-date
• iShares Dow Jones US Real Estate (IYR), down 2.9% year-to-date

Tags: Financial, IAI, IYR, Large-Cap, Real Estate, REITs, RKH, RWR, Sector ETFs, Small-Cap, XLF