A day after hitting another new all-time high, the Dow Jones Industrial Average (DJINDICES:^DJI) was up just 18 points as of 3:30 p.m. EDT Wednesday, and broader indexes weren't moving much, either.

On the economic front, ADP said the private sector in June added 281,000 nonfarm jobs on a seasonally adjusted basis, far more than the 179,000 added in May. This is ahead of the Labor Department's employment report set for release on Thursday, a day early because of Independence Day.  

The other news came from the Commerce Department, which said U.S. factory orders dipped 0.5% in May, driven by fewer orders from the military.  

Why JPMorgan Chase is down today
The big mover in the Dow today is JPMorgan Chase (NYSE:JPM) which was down 1% after CEO Jamie Dimon announced that he has throat cancer. Dimon will undergo treatment this summer, but he intends to stay in his position and said the cancer is "curable." 

Retail banks like this one are just a small piece of JPMorgan Chase's vast empire.

In the short term this brings into question JPMorgan's succession strategy, though the board of directors says it has a plan in place. Under Dimon's leadership, JPMorgan has ballooned to nearly $2.5 trillion in assets in just about every corner of the globe and financial offering imaginable. Managing a bank that large is an extremely complex task, and while Dimon has had his share of ups and downs he's highly respected by investors.

The Wall Street Journal reported that retail executive Gordon Smith and asset management executive Mary Erdoes would be the top candidates if Dimon can't continue as CEO, but there are questions as to whether they have the experience to lead such a diverse bank.

I think investors would be better off if JPMorgan were split into more manageable pieces; that may get more consideration if Dimon steps down.

At the very least, investors are faced with more uncertainty with JPMorgan Chase than they had yesterday. That's something the market doesn't like and that's why the stock is down today.