On Monday, nothing had changed at MongoDB. The software was running, the customers were there, and so were the teams.
And yet, over the course of the day, the company lost nearly a fifth of its stock market value.
The reason comes down to one sentence: its boss, CJ Desai, is leaving for Meta.
What is MongoDB?
You may not know the name, but you almost certainly use its products without realising it. MongoDB sells a database: software that stores and retrieves the information an application needs. Your orders, your messages, the contents of your basket.
It is a solid, established company with thousands of customers. Not a young startup that rests on its founder.
Why Meta came calling
Meta, the parent company of Facebook and Instagram, has embarked on a new race: selling its AI agents to businesses. After the success of its personal assistant launched this month, the group is opening a platform aimed at companies and developers.
The problem is that Meta knows how to talk to the general public, not to IT departments. Selling to a business is a different trade: long contracts, security requirements, relationships of trust built up over years.
The boss of a company like MongoDB knows exactly how to do that. He is the one Meta has chosen to run this new activity. We had already described Meta's ambition to put its agents into your messaging and your payments: now it is targeting businesses.
Why the markets are panicking
An investor who buys a share is not only paying for what the company does today. They are paying for the direction it will take. And that direction is largely set by the boss.
When he leaves without warning, three questions arise at once. Who will replace him? Will the strategy change? And above all: why is he leaving? As long as there is no answer, uncertainty has a price, and the market makes it pay immediately.
Meta, for its part, also fell by around 4% that day. Recruiting a big name does not necessarily reassure the markets.
What to take away
The race for AI is not played out only on chips and models. It is also played out on a much rarer resource: the handful of people capable of turning a technology into a business that works.
And the day one of them changes sides, the market prices it in billions. We return this evening to the question this story raises: how much is one person worth?