FEW people outside finance have heard of Markit. This week afforded two examples of how the company has worked itself into the fabric of the financial system. On July 1st it released a decent set of purchasing-managers’ indices (PMIs), a closely watched series of confidence gauges it compiles each month. That sparked a day-long rally. That same day the European Commission accused 13 big investment banks of having rigged the market for credit derivatives. The complaint also cited Markit for allegedly helping to prevent exchanges from entering the business.

The firm started operations only in 2003. It is variously described as a data provider, an outsourcing partner or a processing expert. None of these labels quite captures the scope of the company. Sitting some distance behind the front lines of global finance, it acts as a provider of back-office services to banks and other investors. Markit staff dub themselves “plumbers in suits”, helping data flow to and from market participants, and within firms too.

This is some way off the pinnacles of high finance, but it has proved a lucrative niche. Fuelled by a string of acquisitions that account for about half its growth, Markit has soared to near $1 billion in expected revenues this year, 3,000 employees and a $5 billion valuation (see chart). If it were to go public, as is perennially mooted, and list in London, where it is based, it would be a contender for the FTSE 100 index. Although it clearly enjoys the perks of being a private firm, with few obligations to detail its accounts, Markit is hardly secretive. Rather, its low profile reflects the disinterest even those on Wall Street take in the infrastructure of markets. That left an opening for Lance Uggla, the firm’s Canadian founder and chief executive. Mr Uggla’s big insight, as a former bond trader, was that opaque market structures made it tricky for banks accurately to price some of the complex financial instruments they were dealing in. Only by pooling their proprietary data could they get reliable marks. The trick was first applied to credit default swaps (CDSs), a sort of insurance policy against borrowers going bust. Unlike shares, CDSs are not traded on exchanges with transparent prices. They are bilateral contracts that give rise to a jumble of erratic price quotes. Only those banks that fed their prices into the Markit system got access to the aggregate data. They also got a majority stake in the company: Markit’s owners include the likes of Goldman Sachs, JPMorgan Chase and UBS. Staff own 30%, a handful of other investors the rest. What came next distinguishes Mr Uggla’s approach from that of Michael Bloomberg, another former bond trader with a successful data franchise. Markit has moved into a broader role as a partner for banks that want to pool or outsource costly non-core activities.

At a facility in Dallas, for example, it receives and processes 7m faxes a year on behalf of customers. Few are of any interest to the recipients—they are mainly updates on the progress of loan repayments—but regulations require that they must be kept on file regardless. Another Markit product helps make sure that complex deals devised by hotshots on trading floors are recorded and processed accurately. Yet another ensures all sides to a transaction are using the same formula when calculating collateral payments. Last year it acquired a company central to securities lending, a practice that enables short-sellers to borrow the shares they want to bet against.

Mr Uggla thinks Markit can double in size again in the next three to five years, and then again shortly thereafter. That would put it in the same league as Bloomberg, Thomson Reuters or McGraw-Hill Financial (the owner of Standard & Poor’s, a ratings agency). Its hope is that post-crisis regulations will prove so complex as to send banks scurrying to Markit asking it to take over even more of their back-office operations.

That may happen. Many banks need to cut costs, and outsourcing is a quickish way of doing that. Markit is also selling more tailored packages that offer to solve financial groups’ headaches by, for example, making sure a firm’s compliance team uses the same bond prices as its accounting department. Geographically, a recent $500m investment from Temasek, a Singaporean sovereign-wealth fund, should help it break out of Europe and North America, source of 90% of its sales.

But plenty of potholes lie ahead. Following the financial crisis regulators have sought to simplify markets, notably by boosting exchanges at the expense of over-the-counter deals. For a company that specialises in bringing light to the murky corners of finance, that is not good news, as Mr Uggla himself acknowledges. (Markit tried but narrowly failed to buy a clearing house, LCH.Clearnet, in 2011.) More generally, the company can look like a conglomerate whose 40 separate product lines are only distantly related. That is partly the result of its acquisitive bent, which itself may have limits.

Antitrust issues are perhaps the biggest worry. Although the EU probe focuses on the CDS market between 2006 and 2009, and although Markit denies any wrongdoing, the investigation may signal that regulators take an increasingly dim view of banks co-operating with each other, especially via a third party in which they have stakes. American antitrust regulators have also made inquiries into Markit.

All sides may be happier if and when the company opts to list its shares, bringing in new investors to dilute the banks. A listing would bring further transparency, too. In the meantime, any hesitation from its biggest customers to push more work out to Markit would seriously dent its prospects. Markit’s ubiquity in such a short time is a tribute to a rare industry success story. It is also a source of vulnerability.