Bulge Bracket

What Does Bulge Bracket Mean?
A slang term used to describe the company or companies who issued the largest amount of securities on a new issue in an underwriting syndicate, or who are the largest underwriting company or companies in the industry.

The bulge bracket is usually the first group listed on the tombstone, which is an advertisement of a new issue.

Investopedia explains Bulge Bracket
In the investment banking industry, syndicates are formed so underwriting companies can share the risks and profits associated with a new security issue with other firms. The larger the new security issue, the more firms are likely to take part in the new issue through syndication, but one firm is likely to act as the manager or co-manager of the syndicate.