Comparison
Lock-Up Period vs Vesting: Key Differences Explained
Vesting is the process by which equity is earned over time — a 4-year vesting schedule means you earn your equity over 4 years, incentivizing you to stay. A lock-up period is a post-IPO restriction that prevents insiders from selling their shares for a set period (typically 180 days after the IPO). Vesting aligns pre-IPO incentives; lock-up periods prevent post-IPO insider selling from crashing the stock price.
What is Lock-Up Period?
A lock-up period is a contractual restriction that prevents insiders (founders, employees, early investors) from selling their shares for a defined period after an IPO, typically 90–180 days. Lock-ups are required by underwriters and the SEC to prevent the immediate insider selling that would signal a lack of confidence in the public company and potentially crash the stock price. After lock-up expiration, insiders can sell shares freely (subject to trading windows and Rule 144 restrictions). Lock-up expirations are closely watched by public market investors because large insider selling can depress share prices. Some companies voluntarily extend lock-ups or impose trading blackouts around earnings to signal confidence.
What is Vesting?
Vesting is the process by which equity ownership is earned over time according to a schedule. The standard startup vesting schedule is 4 years with a 1-year cliff: nothing vests in the first 12 months, 25% vests at the 1-year anniversary, then monthly vesting for the remaining 3 years. Vesting applies to both founder equity (to protect investors and co-founders if someone leaves early) and employee stock options (to incentivize employees to stay). Vesting exists to align equity with contribution: someone who stays 4 years earns all their equity; someone who leaves after 1 year forfeits most of it. Double-trigger acceleration is a common vesting protection: if the company is acquired AND the employee is terminated, unvested equity accelerates.
Key Differences
| Feature | Lock-Up Period | Vesting |
|---|---|---|
| When it applies | Post-IPO (public company) | Pre-IPO (private company, ongoing) |
| Purpose | Prevent insider selling that destabilizes stock price | Align equity with contribution and retention |
| Duration | 90–180 days after IPO | 4 years (standard) |
| Who's affected | All insiders (founders, employees, early VCs) | All equity holders (founders, employees) |
| Forced? | Yes — required by underwriters and law | Yes — required by board and investor agreements |
| Consequence of violation | SEC action, underwriter penalties | Equity forfeited if leave before vested |
When Founders Choose Lock-Up Period
- →Planning personal financial strategy around an upcoming IPO
- →Modeling when insiders can sell post-IPO for financial planning
- →Analyzing IPO timing and the post-lock-up selling risk for stock price
When Founders Choose Vesting
- →Designing an equity compensation package for employees or co-founders
- →Evaluating an offer letter that includes stock options or RSUs
- →Understanding when you've earned your equity in a startup
Example Scenario
A founder has 2 million shares, fully vested after 4 years at the company. The company goes public. The lock-up period prevents her from selling any shares for 180 days post-IPO. On Day 181, she can sell up to a certain amount (subject to trading windows, 10b5-1 plan rules, and company blackout periods). Meanwhile, a new engineer who joins the company 6 months before IPO has a 4-year vesting schedule: they've vested 12.5% of their options by IPO day, but can't sell the underlying shares until after the lock-up AND after their options are exercised.
Common Mistakes
- 1Confusing lock-up expiration with the ability to sell freely — trading windows, blackout periods, and Rule 10b5-1 plans all further restrict insider selling
- 2Not understanding that employees with unvested equity at IPO time must wait for vesting AND lock-up expiration to sell
- 3Founders not planning financial diversification strategy before lock-up expiration — selling too quickly after lock-up sends negative signals
- 4Setting vesting schedules without considering double-trigger acceleration for acquisition scenarios
Which Matters More for Early-Stage Startups?
Both matter at different stages. Vesting drives pre-IPO behavior and equity alignment across the entire company journey. Lock-up periods are a crucial IPO-stage concern for financial planning. Every equity holder should understand both mechanisms, because the combination — vesting schedule + lock-up period — determines when they can actually convert equity to cash.