MKS Instruments (MKSI) RSU sell-vs-hold
Calculator · free · no signup · MKSISell at vest or hold? Compare after-tax payout from selling MKS Instruments RSUs at vest vs. holding through the LTCG cliff at 12 months.
Beta · invite-only · AlphaLatitude Inc. · Free Tools
Your vest
Tax inputs
Hold strategy
Best after-tax payout — at year 1 yr
$47,709
Sell + invest wins by $4,981 over Hold 1 yr.
Estimates only. Not financial advice.
Heads-up: under-withholding. Your employer withholds federal tax at the IRS supplemental rate (22.0% on this vest, ≈ $17,600). Your marginal federal rate on this vest is 32.7%, owing $26,171. Expect to settle the $8,571 gap at tax time.
The hidden purchase
Tax was paid at vest either way. Holding is mathematically equivalent to taking $44,509 in after-tax cash and buying $44,509 of MKSI today.
Most diversification frameworks would advise against a purchase that size in a single name; the right answer depends on your conviction in MKSI. Holding past one year converts the gain to LTCG.
Sell + invest
Best payout| Vest value (shares × price) | $80,000 |
| Federal | |
| State | |
| Medicare | −$1,160 |
| Additional Medicare | −$720 |
| Market gain over 1 yr at 10.0% | $4,451 |
| Cap-gain tax on diversified gain — LTCG (federal + state + NIIT) | −$1,251 |
| Net at year 1 yr | $47,709 |
Sell every share at vest; invest the after-tax cash at the market return for 1 yr, then liquidate. Diversified — no single-stock concentration risk.
Hold 1 yr
| Vest value (shares × price) | $80,000 |
| Vest tax (federal + state + FICA) | |
| Net at year 1 yr | $42,728 |
Sold 444 shares to cover vest tax (net-settled); kept 556 shares 1 yr to qualify for long-term capital gains.
Social Security + Medicare are payroll taxes (collectively called FICA) — they apply because you're still employed at vest.
Both columns are stated in year-1 yr dollars. The sell side compounds at the market return; the hold side compounds at your single-stock expected return after a 20% volatility drag.
Estimates only. Assumes net-settled (sell-to-cover) vesting; double-trigger and pre-IPO RSUs are out of scope. Excludes multi-state moves, AMT interactions on other equity, and 83(b) elections. Not financial advice.
You evaluated one RSU vest. The beta plans every vest of every grant across years, with concentration and AMT in the loop.
Request beta access →Related calculators: RSU Lot Order Calculator · Stock Concentration Calculator
About MKS Instruments
MKS Instruments (MKSI) is a public Semiconductors company, incorporated in Massachusetts and headquartered in Andover, MA.
Equity grants at MKS Instruments typically include restricted stock units (RSUs).
MKS Inc. is a technology company that supplies instruments, subsystems, systems, process control technologies, and specialty chemical products used in manufacturing semiconductor chips, printed circuit board, advanced packaging (semiconductor), and specialty industrial applications. The company also provides chemicals and equipment used for creating decorative and functional surface finishes. The company is headquartered in Andover, Massachusetts, with offices and facilities worldwide.
Source: Wikipedia (CC BY-SA 4.0)
Founded in 1961, the company makes subsystems that go inside semiconductor manufacturing equipment: vacuum and pressure control, gas flow measurement, power delivery, and lasers, sold to tool builders rather than fabs directly. Two large acquisitions reshaped it, Newport in 2016 adding photonics and Atotech in 2022 adding chemistry for printed circuit boards and advanced packaging, the latter funded with substantial debt. Headquarters are in Andover, Massachusetts, and results follow both semiconductor and electronics assembly cycles.
Sources: mks.com · en.wikipedia.org
Equity comp at MKS Instruments
- RSUs use single-trigger vesting: shares become yours as each portion vests on schedule, and the value is taxed as ordinary income at that point. No IPO or acquisition is required.
Researched 2026-08-17.
OptionsAhoy is an independent tool and is not affiliated with, endorsed by, or sponsored by MKS Instruments.
MKS Instruments (MKSI) RSUs vest as ordinary income at the price on vest day. The decision is whether to sell at vest and reinvest, or hold the shares through the 12-month LTCG cliff. This calculator runs both paths through the same after-tax math so you can compare like-for-like.
All MKS Instruments tools → · Use the generic RSU Sell-vs-Hold Calculator for any company. Diversifying multiple RSU lots? See the lot-by-lot sell order →
MKS Instruments equity questions
- Should I sell or hold my MKS Instruments RSUs at vest?
- MKS Instruments restricted stock units (RSUs) are taxed as ordinary income on their value at vest whether or not you sell. The only open decision is what to do with the shares afterward: sell at vest and reinvest, or hold past twelve months for long-term capital-gains treatment on any further gain. The calculator above runs both paths through the same after-tax math so you can compare them directly.
- Does MKS Instruments grant ISOs, NSOs, or RSUs?
- Equity compensation at MKS Instruments typically takes the form of restricted stock units (RSUs). Restricted stock units are taxed as ordinary income when they vest.
- Do MKS Instruments RSUs use double-trigger vesting?
- No. MKS Instruments restricted stock units (RSUs) use single-trigger vesting: each tranche becomes yours as it vests on schedule, taxed as ordinary income at that point, with no liquidity event required.
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