Although going public is almost always a bonanza for the company trying to raise funds, and its existing shareholders, there are big bucks to be made for the companies who help organise the IPOs. The finance giants who take on the role of underwriters are not often in the limelight when it comes to trading, but their roles are crucial. Setting up the public market for the initial sale, for example, can influence how well the first day of trading goes, and assessing the value of the shares about to be released is a factor in determining lasting success. For example, Snap Inc’s recent IPO, which raised the company some $3.4bn, had Morgan Stanley and Goldman Sachs as lead underwriters. But Snap’s subsequent rocky share performance, taking it below its initial price, has confirmed many analysts’ suspicions that the company was overvalued. Such errors aren’t always the underwriter’s fault: Snap, for example, was notoriously secretive about its valuation and process. Morgan Stanley might not mind for long, though: it will reportedly join HSBC and JP Morgan in drawing up what will probably be the largest ever IPO as oil titan Saudi Aramco prepares to sell off a 5% stake.