The flood of foreign investments in US banks gained pace on Tuesday as sovereign wealth funds and other private investors revealed plans to pour $19bn into Citigroup and Merrill Lynch. But as the deals are disclosed, it is becoming clear that not all the investments are being made on the same terms.

At first glance, Citigroup’s decision to raise $12.5bn in convertible preferred securities from a group of investors led by the Government of Singapore Investment Corporation looks like a good deal for the bank.