After several slow years, deals and initial public offerings have roared back, shaking up the Business Journal’s annual list of publicly traded companies in Los Angeles.

Thirteen companies, with a collective market capitalization of more than $16 billion, were added to the list, up from just three newcomers last year with a collective market cap of $2.1 billion. This year’s list includes nine companies that debuted as the result of IPOs.

Meanwhile, 15 companies worth a cumulative $4 billion exited the list, most through acquisitions by competitors or private equity firms outside the region. In almost all those cases, the companies were taking advantage of favorable equity markets or substantially improved economic conditions to make deals.

“In the big picture, this is a very healthy part of the cycle,” said Steve Reiner, managing director at B. Riley & Co. in West Los Angeles. “Companies are looking for the greatest opportunity: For some, it’s through public equity offerings; for others, it’s through private transactions.”

Overall, the net gain of $12 billion in market cap from all these deals helped propel the 165 companies on this year’s list to $670 billion in market value, up 21 percent from last year. (See page 13.) That’s roughly in line with the broader markets as the Standard & Poor’s 500 and Russell 3000 indices both rose about 22 percent during the 12 months ended June 30.

Read the full story in the July 28 weekly edition of the Business Journal.