Methodology & definitions
Every number in NavLens is computed from one source: daily NAVs published by AMFI (via the tigzig API). This page explains each metric in plain English — what it is, why it matters, and how it can mislead you. Nothing here is investment advice.
The Score (0–100)
The score answers one question: “Compared to funds of the same type, how well has this fund balanced returns, steadiness and risk?” It is a percentile within the fund’s own category and plan — a Flexi Cap Direct fund is only ever compared to other Flexi Cap Direct funds. A score of 80 means it beat 80% of its peers on the blend below, not that it returned 80% of anything.
| Ingredient | Weight | What it rewards |
|---|---|---|
| Median 3Y rolling return | 30% | The typical outcome across every possible 3-year holding period — not one lucky window |
| Rolling consistency | 20% | The share of all 3-year periods that beat 8% a year — steadiness |
| Sharpe ratio (3Y) | 25% | Return earned per unit of volatility, above a 6.5% risk-free rate |
| Max drawdown (5Y) | 15% | Shallower worst-case falls |
| 3Y CAGR | 10% | Recent absolute performance |
Each ingredient becomes a percentile rank inside the peer group; the score is their weighted average. 75% of the weight goes to consistency and risk-adjusted behavior, only 10% to raw recent returns — because trailing returns are the easiest number to be fooled by.
The n/5 coverage badge. Young funds are missing ingredients — a 3-year-old fund has no rolling-return history, so its score rests mostly on Sharpe and recent CAGR. The badge shows how many of the 5 ingredients the score actually used. 2/5 means “hot recent run, unproven” — treat it with suspicion. 5/5 means the full methodology applies (needs roughly 6+ years of history).
Limits, honestly: the score is relative (top of a weak category is still weak), backward-looking (past performance persists weakly at best), and blind to fundamentals (the data has no expense ratios, AUM or manager changes). Use it to shortlist within a category you already chose — never as a buy signal, and never to compare across categories.
The metrics
CAGR (1Y / 3Y / 5Y / 10Y)
- What it is ·
- Compound Annual Growth Rate — the single steady yearly rate that would turn the starting NAV into today's NAV over that period. Under 1 year it's shown as the simple return.
- Why it matters ·
- The standard way to compare growth across funds and periods.
- Watch out ·
- It's point-to-point: it depends entirely on the two dates chosen and hides everything in between. A fund that crashed and recovered shows the same CAGR as one that grew steadily. That's why NavLens leans on rolling returns instead.
Rolling 3Y return (median, consistency)
- What it is ·
- Take every possible 3-year holding period in the fund's history (starting each month), compute the annualized return of each, and look at the whole distribution. The median is the typical outcome; consistency is the share of windows that beat 8% a year.
- Why it matters ·
- This is what a real SIP investor experiences — you don't get to pick the perfect start date. A fund with a 19% median and 95% consistency has been good to almost everyone who held it 3 years, whenever they started.
- Watch out ·
- Needs at least ~6 years of history to mean anything (NavLens requires 12 windows minimum). The 8% threshold is a judgment call — roughly what a safe deposit-like alternative earns.
Volatility (3Y annualized)
- What it is ·
- How much the fund's daily returns bounce around, scaled to a yearly number. Computed from 3 years of daily NAV moves.
- Why it matters ·
- Two funds with the same return are not equal if one is twice as jumpy — the jumpy one is harder to hold through a crash without panic-selling.
- Watch out ·
- Volatility punishes upside jumps as well as downside ones, and calm markets flatter everyone. Read it together with max drawdown.
Max drawdown (5Y)
- What it is ·
- The deepest peak-to-trough fall in NAV over the last 5 years. −35% means at some point the fund lost 35% from its high.
- Why it matters ·
- The most visceral risk number: it's what you would have watched happen to your money. It predicts whether you'd have stayed invested.
- Watch out ·
- Past drawdowns understate what's possible — every 'worst ever' was exceeded once. Young funds that haven't lived a crash show flatteringly shallow numbers.
XIRR (SIP Lab)
- What it is ·
- The annualized return of an actual stream of monthly investments, accounting for the fact that each installment was invested for a different length of time.
- Why it matters ·
- For a SIP, XIRR is your true personal return — plain CAGR overstates or understates it because your money went in gradually.
- Watch out ·
- Early installments dominate long simulations; recent market moves barely change a 10-year XIRR.
Fund facts & common holdings (AI-extracted)
- What it is ·
- For funds in your plan or watchlist, an AI agent (Claude) searches the fund's latest official disclosures — AMC factsheets, AMFI TER pages — and extracts expense ratio, AUM, exit load and top holdings, always with the source URLs it used. Common holdings shows stocks appearing in the top holdings of 2+ plan funds.
- Why it matters ·
- None of this exists in any free NAV API, and top-holdings overlap is the direct answer to the 'same stock in 7 funds' problem that correlation can only hint at.
- Watch out ·
- AI extraction can err — every value links its source; verify before acting. Holdings disclosures are monthly and cover only the top ~10-15 positions, so real overlap is somewhat higher than shown. Data refreshes at most every 20 days.
Overlap (SIP Planner)
- What it is ·
- Correlation of two funds' daily returns over 3 years, from −1 to +1. LOW < 0.75, MED 0.75–0.90, HIGH > 0.90.
- Why it matters ·
- Funds holding the same stocks move together. If two funds correlate at 0.95, owning both is mostly owning one fund twice — diversification on paper only. This is the pattern that made a 10-fund portfolio hold HDFC Bank 7 times.
- Watch out ·
- It's a proxy — the AMFI data has no actual holdings. Two funds can correlate highly while holding different stocks in the same sector, and correlations rise in crashes exactly when you want diversification most.
Exposure: Domestic / International / Commodity
- What it is ·
- What actually drives a fund's returns. Domestic = Indian equity/debt markets. International = foreign markets (Taiwan, US, EM, global). Commodity = gold/silver prices, whatever the fund's legal structure.
- Why it matters ·
- AMFI's official category can't tell you this — a Taiwan fund is officially 'Sectoral/Thematic' and an S&P 500 index fund is just 'Index Funds', because only fund-of-funds get the 'FoF Overseas' label. And a silver FoF is officially 'FoF Domestic' (it holds Indian-listed ETFs) while its returns are global silver × USD/INR. NavLens classifies by economic exposure instead.
- Watch out ·
- Name-based inference at the edges. International funds add currency risk and often double-layered expense ratios; commodity funds have no earnings growth engine — they're a hedge, not a compounder.
Geography estimates
- What it is ·
- Region weights guessed from fund names (a Taiwan fund → Taiwan; a global innovation FoF → mostly US; a domestic fund → India).
- Why it matters ·
- Gives a rough view of where your monthly SIP actually lands geographically.
- Watch out ·
- These are estimates, not holdings data. Treat percentages as a sketch, ±10 points.
The data & its limits
- Source: AMFI daily NAVs, aggregated by the tigzig MF NAV API — 18,000+ schemes back to 2008, refreshed nightly (2:30 AM IST). The full history is mirrored in NavLens’s own database, so charts don’t depend on third-party uptime. The “Data as of” date is in the header.
- The dataset contains only NAVs, scheme names and ISINs. There are no holdings, AUM, expense ratios, dividends or manager data — anything NavLens says about categories, geography or overlap is inferred and labeled as such.
- Categories, fund houses and the open/close-ended flag come from AMFI’s official daily scheme list (NAVAll.txt) where available; delisted schemes absent from that list fall back to name-based inference. The “international” marker is NavLens’s own: it flags non-India exposure even where AMFI files a fund under a domestic-sounding category (e.g. a Taiwan fund officially labeled Sectoral/Thematic).
- Returns ignore taxes, exit loads, and expense-ratio changes. IDCW (dividend) plans’ NAVs drop on payout, so growth-plan NAVs are the meaningful ones for return math.
- Past performance does not predict future returns. NavLens is a research lens, not advice.