Order Reprints Print Article Covid-19 has accelerated a move by clients to digital platforms, which will be a strength for WPP and its stock. Benjamin Fathers/AFP/Getty Images Text size The world’s largest advertising agency, WPP, is seen as a bellwether for the economic health of different sectors because marketing budgets tend to be axed first in tough times—and dusted off first when things pick up. The company, which counts Ford Motor and L’Oréal as clients, duly crashed about 22% over the past year during the pandemic as clients looked to cut costs. Meanwhile, it has been trying to bounce back after the departure of