DENVER, Aug. 25 -- Palantir Technologies paid $15.4 million of income tax in the three months to June 30. It earned $1.08 billion before tax over the same period. The rate works out at 1.4 per cent, and it is the least examined number attached to a stock that has risen more than 43 per cent in a month.

The shield is old failure. Between 2018 and 2022 Palantir lost $3.22 billion, and American tax law lets a company carry those losses forward against later profit. The years when Palantir was a cautionary tale about unprofitable software are now the years underwriting its margins.

Palantir fell 1.93 per cent to $176.47 on Monday afternoon in New York, one of the few large software names to give ground in a session that punished anything ma...