This free, data-driven calculator lets you estimate what a SIP (Systematic Investment Plan) or a lumpsum investment in Supernus Pharmaceuticals, Inc. (SUPN) would be worth over any period from 1 month to 15 years, using the stock's actual historical price data — fully adjusted for splits and dividends. Unlike generic calculators that ask you to guess an expected return, this tool reads SUPN's real closing prices and computes the Compound Annual Growth Rate (CAGR) for exactly the number of months you select. The CAGR shown is always annualised, so whether you pick 6 months or 10 years you can compare apples-to-apples with fixed deposits, mutual funds, or any other benchmark.

What is CAGR and why does it matter?

CAGR — Compound Annual Growth Rate — is the single most important number when evaluating long-term stock performance. It answers the question: "If this investment grew at a steady rate every year, what would that rate be?" A stock that doubles in 6 years has a CAGR of approximately 12.2%, regardless of whether it went straight up or took a rollercoaster path. For SUPN, the 1-year CAGR stands at 52.5%, 3-year CAGR stands at 13.4%, 5-year CAGR stands at 10.1%, 10-year CAGR stands at 9.5%, 15-year CAGR stands at 16.8%. These figures are computed from month-end adjusted closing prices and updated regularly.

How the SIP calculator works

A SIP (Systematic Investment Plan) means committing a fixed amount — say $500 — every month. Each instalment buys SUPN shares at that month's price, so you automatically buy more units when the price is low and fewer when it is high (dollar-cost averaging). The future value of a SIP is calculated using:

FV = P × [((1 + r)ⁿ − 1) / r] × (1 + r)

where P = monthly investment amount, r = monthly rate derived from SUPN's annualised CAGR (annual CAGR ÷ 12), and n = the number of months selected. The CAGR is automatically recalculated every time you move the time-period slider, so the projection always reflects what SUPN actually delivered over that exact window — not a guess.

How the Lumpsum calculator works

A lumpsum investment means deploying your entire capital on day one and holding. The future value formula is simply: FV = P × (1 + CAGR)^years. Because lumpsum is more sensitive to the entry price, the Lumpsum tab is useful for answering "what if I had invested $10,000 in SUPN N months ago?" The calculator uses the same CAGR derived from actual price history for the selected period, making the result grounded in real market data rather than an assumed rate.

SUPN historical lumpsum results ($1,000 invested)

Based on SUPN's actual adjusted closing price data: $1,000 invested in Supernus Pharmaceuticals, Inc. 1 year ago would be worth approximately $1,525 today. $1,000 invested in Supernus Pharmaceuticals, Inc. 3 years ago would be worth approximately $1,458 today. $1,000 invested in Supernus Pharmaceuticals, Inc. 5 years ago would be worth approximately $1,619 today. $1,000 invested in Supernus Pharmaceuticals, Inc. 10 years ago would be worth approximately $2,478 today. $1,000 invested in Supernus Pharmaceuticals, Inc. 15 years ago would be worth approximately $10,285 today. Past performance is not a guarantee of future results, but these numbers illustrate the power of long-term compounding in high-quality growth stocks.

SUPN best and worst calendar years

Knowing the range of annual outcomes helps set realistic expectations. SUPN's best calendar year was 2016 with a return of +87.9%. Its worst calendar year was 2019 with a return of -28.6%. The annual-returns bar chart in the sidebar visualises every year since 2011, giving you an at-a-glance view of volatility, recovery speed, and growth consistency. Investors who stayed invested through the down years were rewarded in subsequent recoveries — a pattern that repeats across most quality large-cap stocks.

SIP vs Lumpsum — which is better for SUPN?

For volatile stocks like SUPN, SIP generally reduces timing risk because you spread your cost across multiple months. In years where the stock dips mid-year and recovers strongly, SIP investors often accumulate more units at lower prices, boosting their effective return. Lumpsum, on the other hand, maximises gains when the entry point coincides with a multi-year low — the classic "buy the dip" scenario. A practical approach is to use the SIP tab to model a disciplined monthly investing habit and the Lumpsum tab to evaluate a one-time deployment, then compare total values side by side.

How to use this calculator

Step 1 — Choose the tab: SIP for monthly investing or Lumpsum for a one-time investment.
Step 2 — Enter your investment amount using the input field or the slider.
Step 3 — Drag the Time Period slider to select how many months you want to model — from 1 month up to 15 years (180 months). The CAGR (p.a.) badge updates instantly to show SUPN's actual annualised return for that exact window.
Step 4 — Read the results: Invested Amount (what you put in), Est. Returns (gain or loss), and Total Value (your projected portfolio value). The donut chart on the right visualises the invested vs returns split.

⚠️ Disclaimer: Past performance is not indicative of future results. This calculator is provided for informational and educational purposes only and does not constitute financial advice or a recommendation to buy or sell any security. CAGR figures are derived from historical adjusted closing prices, adjusted for stock splits and dividends reinvested. Actual returns will vary based on the exact dates of purchase, transaction costs, taxes, and prevailing market conditions. Always consult a qualified financial advisor before making investment decisions.