It’s been a good week for shares in Corporate Travel Management, up 10.3 per cent since Monday. Almost half of those gains came during Wednesday’s session, presumably in reaction to news from Jersey City that American Express Global Business Travel, the world’s biggest travel management company, had been recapitalised, giving the business an enterprise value of $US5 billion ($7.3 billion).

While American Express itself is a public company, Amex GBT is privately held. It is half-owned by Amex and (now) half-owned by 12 investors including private equity giant Carlyle, funds manager BlackRock, sovereign funds GIC (Singapore) and Qatar Investment Authority and California healthcare giant Kaiser Permanente. Thus, its profitability is not publicly disclosed and – self-evidently – an earnings multiple cannot be determined from its new enterprise valuation.