IPO lock-up is a schedule, not a cliff
Before you plan to sell, map your holder class, release caps, earnings windows, and tax dates instead of waiting for a fixed unlock date.
Anthropic, the AI company that filed its S-1, the public filing, on October 26, 2026, linked its IPO lock-up to earnings dates rather than a flat 180-day release. The trap is treating that structure as a cliff. The rule is to read it as a holder-class schedule of release caps, dates, and trading windows.
It applied to list on Nasdaq under ticker ANT. For employee stock options, the question is not only when the lock-up ends. It is which slice you can sell, when, and at what tax cost.
The schedule is the document, not the rumor
Many IPO lockups use a single 180-day period before insiders can sell. The S-1 lock-up follows earnings dates instead of a fixed calendar. That distinction matters because the first tradable slice can arrive before the date most people quote.
Your unlock dates come in order
Identify your holder class. The filing describes four distinct groups: standard employees, certain stockholders, large holders above the 0.5% fully diluted threshold, meaning all potential shares are counted, and founders. Done looks like a short answer: you know which category controls your release caps.
Read the release caps. For employees, officers, and non-founder directors, the filing permits a 10% sale on the first trading day and a later 35% sale after full-year 2026 results. Holders below 0.5% release 6% on day 27, then 6% on day 48, then 7% on day 62, and 7% on day 76. Done looks like a clear list: window, percentage, and what remains locked.
Put the dates in order. The filing includes a window after full-year 2026 results around February–March 2027 and a window after Q1 2027 results or 180 days around April–May 2027. Holders above the 0.5% fully diluted threshold stay locked until Q3 2027 earnings or Day 365, whichever comes first. Done looks like a date list with a few sell dates, not a fixed anniversary.
Check the trading windows. The lock-up includes a first-trading-day window that permits sale of up to 10% of locked shares. A few insiders may sell on the first day, well before the usual 180-day lock-up. Done looks like a clear answer to “Can I sell now?” for each date on your date list.
Do not assume the early window is the whole plan. The mistake is selling into the early window without checking whether the next window lands after an earnings release. If the next window is tied to results, the price can move before you get to the next slice.
Model IPO taxes and liquidity. Before you sell, estimate the tax on the slice you plan to release, your cost basis, and the cash you need. Done looks like a number you can live with: the after-tax amount, not just the share price.
Decide what to sell in each window. Ask whether the slice is large enough to cover taxes, reduce concentration, or meet a cash goal. If the next window is close, you may sell less now and keep optionality. If the next window is far, the early slice may be your best chance to lower risk. Done looks like a written plan: sell this many shares in this window, hold the rest for this reason.
Keep a simple file. Store the filing, your grant documents, the holder-class answer, the release caps, the date list, and the after-tax math in a shared file. When the trading window opens, you should not be hunting for the rule. You should be comparing the price, the tax bill, and your plan. Done looks like a quick check: the rule, the price, the tax bill, and your plan are ready.
The example is a template
The Anthropic IPO lock-up is a useful example because it is tied to earnings dates. It shows how a staggered lockup can give you more dates to plan around. It also shows why the lock-up schedule matters more than a single date. If you hold options at a company that goes public, the same reading rule applies: class, cap, date, window, tax.
