Amid a long-running bull market, it can be easy to forget that trust in our market system is built on the subtle rules that guide interactions. Now, a crucial investor safeguard is under attack by the very institution whose mission it is to protect investors and promote transparency.

The US Securities and Exchange Commission has proposed, in a 3-2 vote, to limit longstanding investor rights to request shareholder input on annual proxies. From my decades-long experience educating and advising corporate boards, this proposal could not have come at a worse time.