Analysts said the selling reflected concerns whether the financial reports would justify recent stock gains.
The law seeks to hold top executives personally responsible for the financial reports of their companies.
The financial reports are a detailed accounting of money collected and spent by super-pacs.
Another step taken by the authorities is to check the financial reports of power distributors.
Daly said the union had seen the financial reports for seven years and had never disputed them.
There were plenty of oddities in the financial reports filed by presidential campaigns on Thursday with the Federal Election Commission.
In some cases, the matters being tested were too unimportant to contribute to a material misstatement in the financial reports.
Instead they are fixing up the ones they have, a trend that is beginning to show up in the financial reports of retailers.
"The financial reports filed after Sept. 30 will set the tone for the last 100 days before people start voting and caucusing," Mr. Obama wrote supporters.
The financial reports also tell us how much each person on Facebook is worth to the company, which varies by country.
