NEW YORK (

TheStreet

) -- The

Dow Jones Industrial Average

TST Recommends

may be trading sharply lower today, but the blue-chip index is still set to notch its best August in nine years.

Despite Monday's 90-point decline, the Dow is still higher by 3.2% in August, its best performance for the month since August 2000, when it rose 6.6%. At the end of today's session, the Dow will have closed out a second straight month with gains, and five of the last six will have been winners.

From there, the news gets mixed. Of those five up months, August's performance will be the smallest. Additionally, the Dow is off 126 points from this month's closing high of 9580.63, which it hit on Thursday.

Disney

(DIS) - Get Report

was the biggest decliner Monday, falling 3.1% after the House of Mouse announced it will buy

Marvel Entertainment

(MVL)

for a combination of cash and stock. While Marvel shares jumped 25%, Disney investors didn't welcome Spiderman and the X-Men with open arms.

Marvel shareholders

will receive $30 cash plus 0.745 Disney shares for each Marvel share they own. Based on Friday's closing stock prices, the deal values Marvel at about $4 billion.

Among the Dow's 27 other decliners,

Boeing

(BA) - Get Report

,

Caterpillar

(CAT) - Get Report

and

Cisco Systems

(CSCO) - Get Report

fell more than 2.1%.

On the positive side,

JPMorgan Chase

(JPM) - Get Report

was the top-performing Dow stock, rising 1.4%.

Merck

(MRK) - Get Report

and

Wal-Mart

(WMT) - Get Report

were the only other winning stocks at midday.

Looking ahead, Tuesday marks the beginning of September, which is typically a challenging month for equities. Additionally, Paul Nolte, director of investments with Hinsdale Associates, points out that the beginning of a new month brings the heavyweights of economic reports, including the government's employment report and data from supply management reports on manufacturing and services.

"Estimates for employment are a slight rise with payrolls shrinking by an ever-smaller amount," Nolte wrote in an email. "While the weekly unemployment claims figures indicate payroll losses in the 300,000 range, the markets are expecting just over 225,000."

If September is already considered a bad month for equities historically, a misstep this early could be even more disheartening for bulls.

-- Written by Robert Holmes in New York

.