WASHINGTON — The day after Representative Eric Cantor became the first congressional leader in modern times to lose his seat in a primary, one of the biggest aftershocks occurred not on Capitol Hill or in the sprawling Richmond suburbs he has represented for more than a decade but on the New York Stock Exchange.

The share price of Boeing tumbled, wiping out all the gains it had made this year, a drop analysts attributed to the startling defeat.

While he was often an adversary to both the Tea Party and Democrats in Congress, Mr. Cantor, a Republican and the House majority leader, was also a powerful ally of business big and small, from giants like Boeing to the many independently owned manufacturers and wholesalers that rely on the federal government for financial support.

His loss at the hands of David Brat, a Tea Party-inspired economics professor who campaigned on throwing corrupt Wall Street bankers in jail, railed against crony capitalism and insisted that immigration reform would only reward lawbreakers, spurred business leaders to mobilize to preserve their clout in Congress. Already uneasy over what they see as an especially hostile strain of anticorporate populism growing within the conservative movement, and threatening the traditional corporate-friendly centers of power inside the Republican Party, many businesses fear the loss of some of their strongest champions on Capitol Hill.