The Williams Act which became law in 1968 regulates disclosure of tender offer bids to protect investors. All details of the bid must be outlined in a filing with the SEC.

If public, both target and acquirer must disclose merger activity to the SEC.

Terms of specific mergers or acquisitions must be disclosed in the company's 8-K report to the SEC. (8-K reports must be filed within four days of the triggering event)

Terms can also be included as exhibits to the company's 10-K or 10-Q reports.

If the merger or acquisition requires a vote by shareholders, the agreement will be available in the proxy document, Schedule 14A (or sometimes an information statement, Schedule 14C). The proxy will include the terms of the merger and what shareholders can expect to receive as proceeds.

Schedule 14A's are filed as PREM14A and DEFM14, preliminary and definitive statements.

Use SEC filings to find details about a company's merger or acquisition.  Both the target and acquirer will file reports. The actual report type (8-K, 10-K, or proxy) will vary.

Use the database Thomson One to find the SEC merger filings. Search for the company by ticker and then open the "Deals" tab.  Scroll down to the "Deal Synopsis" section for access to deal filings and news (press releases) from both the target company and the acquirer company. Filings cover the period from when the merger was announced until it was completed.

Use the database Audit Analytics to find SEC merger filings.  Search for the company by ticker and from the company profile page scroll down to "Transactions" for links to deal filings.

Several types of SEC filings could signal merger-related activity.

The 13D - Filed by an individual or group that owns 5% or more of the outstanding stock of a company.

Form 4 - Filed by an owner or insider who buys or sells stock of a company.