Footnoted has compiled some research on the SEC’s mid-year statistics on corporate disclosures, based on figures compiled by Morningstar Document Research.

Some highlights include:

• Financial firms generate the greatest number of filings. Both this year and last, BlackRock made the most filings, with 2,368 and 2,313 in the first halves of 2011 and 2010, respectively.

• Barclays, FMR, Bank of America, and JP Morgan Chase round out the top five in terms of number of filings.

• International Speedway, with 669 filings for the company’s $1.5 billion market cap, is the only non-financial company to crack the top 20.

• Peer-to-peer lending firms LendingClub Corp. and Prosper Marketplace, neither of which is publicly traded, also stand out among the most prolific filers.

• Enzyme-maker Verenium’s 6,280-page 10-Q was the longest filing during the first half of 2011.

• Demonstrating that the heftiest filings don’t always come from the biggest companies, tiny First Asia Holdings Ltd., a Hong Kong nutritional-supplement company with a market-cap of $35.3 million, produced the biggest filing of the first half of 2011, at 202 MB.

Overall, filings are up by about 5% to 375,909 compared to the same period last year. Meanwhile, the lengthiest filings are also getting longer—while the top 20 filings in the first half of 2010 totaled 52,514 pages, the top 20 so far this year amount to 56,571 pages, an increase of nearly 8%.