What happened: On Dec. 3, 1986, Boston's owners sold a 40% stake through an IPO of 2.6 million shares. Roughly 95,000 investors bought units, which traded under the symbol BOS until the franchise's 2002 sale began its return to private ownership.

Why it matters: The structure gave fans direct equity while allowing the ownership group to recover more than its reported $15 million purchase price. Printing and mailing investor distributions cost roughly $1 million a year.

What to watch: Full control under Boston's latest ownership sale is due to transfer to Bill Chisholm's group by 2028. The approved structure could put the final valuation at $7.3 billion.