WASHINGTON—Hedge funds and other rapid-fire investors can get access to market-moving documents ahead of other users of the Securities and Exchange Commission's system for distributing company filings, giving them a potential edge on the rest of the market.

Two separate groups of academic researchers have documented a lag time between the moment paying subscribers, including trading firms, newswires and others, receive the filings via a direct feed from an SEC contractor and when the documents are publicly available on the...