Fastly (FSLY) Stock Concentration Calculator
Calculator · free · no signup · FSLYQuantify Fastly concentration risk. Drawdown impact at 30 / 50 / 70%, with the tax-aware trade-off between selling down and hedging.
Beta · invite-only · AlphaLatitude Inc. · Free Tools
Your inputs
Adjust — results update instantly.Position & portfolio
Tax
Most fee-only advisors target ≤10% in any single name. You're at 67%.
Estimates only. Not financial advice.
Most sensitive to: Expected market return (±10% on this input swings best-plan wealth by ±$190,508).
Cost of fully de-concentrating
All three plans sell to 0% (no hedge).Sensitivity. If your expected position return drops below 19.6%/yr, lump-sum (sell everything today) beats every spread plan above.
Have multiple RSU vest lots? The RSU Lot Order Calculator picks which lots to sell first, and on which dates, to divest at the lowest computed tax.
Build your own plan
Toggle below — chart updates live. Sell buttons show the slice.Tech / Software single names hit a 50%+ peak-to-trough drawdown in roughly 1 of every 5 rolling 3-year windows over 2014–2024. Even mega-caps aren’t exempt.
Tax brackets: 2026 · Estimates only — not financial advice.
Estate note. Heirs receive a stepped-up basis at death (§1014), eliminating built-in gain on inherited shares. Older holders who plan to bequeath rather than sell may rationally never de-concentrate.
You sized one position's risk. The beta integrates hedging, sell-down, and tax timing into one optimized plan.
Request beta access →Related calculators: Protect Your Stock Calculator · RSU Lot Order Calculator · Equity Funding Plan Calculator
About Fastly
Fastly (FSLY) is a public Cloud/SaaS company, incorporated in Delaware and headquartered in San Francisco, CA.
Equity grants at Fastly typically include restricted stock units (RSUs).
Fastly, Inc. is an American company based in San Francisco, which describes itself as a cloud computing company. Fastly provides content delivery network services, image optimization, and load balancing services. Fastly's cloud security services include denial-of-service attack protection, bot mitigation, and a web application firewall.
Source: Wikipedia (CC BY-SA 4.0)
Artur Bergman founded the company in 2011 to build a content delivery network that developers could reconfigure in seconds rather than hours, with edge compute and instant purging as the differentiators. Customers include news sites, ecommerce, and streaming platforms that need cache invalidation at speed. A 2021 configuration bug took down a large slice of the web for about an hour, including government and media sites, which demonstrated concentration risk in the CDN layer. The company competes with Cloudflare and Akamai and is headquartered in San Francisco.
Sources: fastly.com · en.wikipedia.org
Equity comp at Fastly
- 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 Fastly.
If a meaningful share of your net worth sits in FSLY, concentration risk is the question. This calculator quantifies drawdown impact at 30 / 50 / 70%, and the trade-off between selling down (tax cost now) versus hedging (option premium drag), auto-filled with FSLY's option-implied volatility.
All Fastly tools → · Use the generic Stock Concentration Calculator for any company. Diversifying multiple RSU lots? See the lot-by-lot sell order →
Fastly equity questions
- How much FSLY stock is too much?
- There is no single threshold, but the larger the share of your net worth in one stock, the more a single bad year can set back your plans. The calculator above quantifies the drawdown impact at 30, 50, and 70 percent for your FSLY position and weighs selling down (which triggers capital-gains tax now) against hedging (which costs option premium).
- Does Fastly grant ISOs, NSOs, or RSUs?
- Equity compensation at Fastly typically takes the form of restricted stock units (RSUs). Restricted stock units are taxed as ordinary income when they vest.
- Do Fastly RSUs use double-trigger vesting?
- No. Fastly 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.
One piece of the puzzle.
OptionsAhoy plans your Fastly equity alongside hedging, vesting, and de-concentration, across bullish, neutral, and bearish market scenarios. Free during beta.