Authored by Michael Moritz, Chairman of Sequoia Capital, originally published Op-Ed via The Financial Times, The private and public worlds of technology collided this week with a set of stories about two very different companies: one a large business in its fourth decade, seeking to adjust to a new world; the other a much touted Silicon Valley start-up whose ambitious scientific claims were questioned in a devastating newspaper article. The former, Dell, and the latter, Theranos, illustrate the benefits and perils of life as a private company. Michael Dell had experienced many years as the head of a publicly traded company, which included some close encounters of the worst kind and a bruising battle with some dissident shareholders, before delisting in a leveraged buyout in 2013. Since then, relieved from the merciless roasting of the quarterly earnings call, he has had the freedom to undertake a long-term restructuring of his business. Mr Dell emerged from the shadows this week to announce his intention to purchase EMC, the large storage provider, in what would be the biggest technology takeover in history. If Mr Dell illustrated the benefits of privacy, Elizabeth Holmes, the chief executive and founder of Theranos, has just learnt that even for the head of a high-profile, secretive Silicon Valley company valued at $9bn, a light will eventually illuminate dark places. Ms Holmes formed Theranos in 2003 to provide health tests from a few drops of blood rather than what gushes out of several tubes. Ms Holmes ingeniously convinced some very accomplished people (including Oracle’s Larry Ellison) to furnish her company with about $400m and has persuaded two former US secretaries of state, a former US defence secretary and the former chairman of the Senate Armed Services Committee to join her board of directors. That feat of persuasion may have been even more impressive than it seemed. The Wall Street Journal this week reported claims that the company’s proprietary technology — whose co-inventor committed suicide two years ago after telling his wife that it was not effective — is used only in a small fraction of the company’s tests, with others performed using standard laboratory equipment in a way that might produce inaccurate results. Former employees of Theranos told the newspaper they had been instructed to deal with regulatory checks on its test results in a way that might amount to cheating. Theranos contests these suggestions of scientific trickery and legerdemain. However, if they turn out to be true, the company could be mortally wounded — a development that might make technology investors sit up straight and be less credulous as they scrutinise investments. Life in the shadows of the private market has many benefits for emerging companies. It allows them to experiment, work out kinks in a product, lure talented people with attractively priced stock options, shield themselves from the scrutiny of predatory competitors and stutter in private until they can speak fluently in public. It is also a refuge to which people such as Mr Dell can retreat once their companies no longer offer public investors either the growth or predictably for which they yearn. But there is also a false sense of security provided by the private markets at a time when interest rates are negligible and many investors, particularly those who are either new to technology or have short memories, are all too willing to back start-ups whose premises house several baristas and where a dozen blends of tea (not to mention the sea-salt flavoured chocolate bars and bio-dynamically raised Anjou pears) are de rigueur. It is easier to conceal weaknesses, present an aura of invincibility and confound investors as a private company that can escape by making few disclosures than as a publicly traded one. One glance at the list of so-called unicorns — those private technology companies valued at more than $1bn — illustrates this point. A handful of these businesses will become the great, enduring companies of tomorrow. But a good number seem the flimsiest of edifices. Forget the fact that some of these valuations are illusory because the most recent investors have structured their investments as debt in all but name, meaning that they will stand to profit even if the company is worth far less. The more salient point is that for the past three or four years private investors have just been more forgiving than their public market counterparts, who, had they been presented with the most recent financial reports of a good number of these companies, would have decimated the stocks. In the past few quarters, the founders of several technology companies have discovered a far chillier reception as they tramped around on initial public offering roadshows than they were accorded in the private shadows. Most of the leaders of the subprime unicorns who continue to enjoy the fruits of the private market delude themselves about the difference between control and discipline. Some say that if their companies become public they will lose control. Google, Facebook and a raft of other companies with dual-class stocks put paid to that argument. What the heads of the subprime unicorns really mean is that the sort of disclosure required of a public company is the picture they do not want to view. But as Ms Holmes of Theranos discovered this week, eventually there is no place to hide.