A sweeping victory for Joe Biden and Kamala Harris in November’s US election plus Democratic majorities in both houses of Congress would be the best outcome for the US economy in the long run — though investors might take fright in the first few weeks.

That’s the take of Fidelity International, the sister company of Fidelity Investments, and its lead cross-asset strategist Wen-Wen Lindroth, published in a note on 13 August after Biden picked Harris as his running mate.