The honest answer most equity-comped tech workers do not get from company comms. Three drop scenarios scored against historical reality, plus the survivorship-bias warning.
The single stock as a share of investable net worth, plus what kind of company it is.
Share of investable net worth in this single position
| Scenario | Probability | Stock impact | NW impact |
|---|---|---|---|
| Down 30% from peak | 75% | -£30,000 | -6.0% |
| Down 50% from peak | 35% | -£50,000 | -10.0% |
| Down 70% from peak | 12% | -£70,000 | -14.0% |
| Down 90%+ or bankruptcy | 5% | -£95,000 | -19.0% |
High concentration. A bad year here meaningfully reshapes net worth. The historical record suggests setting a sell schedule. Probabilities scaled to a 5-year holding horizon. Longer horizons compound both upside and drawdown risk.
Illustrative figures only. Drawdown probabilities are order-of-magnitude figures from long-run single-stock studies, anchored to a five-year baseline and scaled to the user's horizon. For your specific situation, consult a qualified adviser.
Worth tracks every grant, every vest, every spot exposure across the household, and surfaces the concentration band before a bad month does. Join the waitlist.
Every employee of every company in the long tail felt the same way. They had inside information, conviction, and pride in the work. The market does not reward conviction; it rewards being right. The right move is not to question your conviction, it is to size the bet so that being wrong is survivable.
For most advisers, under ten per cent of investable net worth per single stock is the standard guideline. Under five per cent is conservative. Above twenty-five per cent means a single corporate event can reshape your retirement. Above fifty per cent means you have a job and a portfolio with the same dependency.
That is exactly the survivorship-bias trap. For every Apple there are dozens of comparable-at-the-time companies (Lucent, Cisco at the top, Sun, BlackBerry, Yahoo, Nortel) that are now footnotes. You cannot tell which one you have got in advance. Position size accordingly.
Unvested grants are forced concentration; you cannot sell them. The lever you control is what happens at vest: sell immediately and diversify, or hold for capital-gains treatment. The default answer for most people most of the time is sell at vest, then diversify.