Asset correlation and diversification analyser

Analyse local price CSVs using returns on shared dates. Compare correlation, interval volatility and a supplied fixed-weight portfolio without market connections.

Inputs

Hypothetical example. Replace these inputs with your own.

Single quote currency for all pricesPrice observations (paste the documented CSV)

Asset weight 1CSV asset labelPortfolio weight · %

Asset weight 2CSV asset labelPortfolio weight · %

Local CSV (read in this browser)

Browser-selected files are not uploaded. Without JavaScript, pasted CSV is sent transiently to PHP on this website. Use the documented format below. Required records are not inferred or filled in.

Select one combined file or up to eight files. Each header must be date,asset,price, followed by plain unquoted rows such as 2025-01-01,A,100. Combined maximum: 1 MiB and 16,000 observations, with two to eight exact asset labels. Supply matching weights totaling 100%. File order determines the saved digest.

Result

Calculation result

Example result

Portfolio sample volatility per aligned interval: < 0.00000001 %
Weighted standalone interval volatility: 11.54700538 %
Standalone volatility / portfolio volatility: 3,602,879,701,896,400 ratio
Common return intervals: 3 count
Shared price dates: 4 count
Assets: 2 count
Price rows outside shared dates: 0 count

Price dates are intersected across all assets before simple returns are computed. No price correlation, forward fill or interpolation is used.
Volatility is sample standard deviation per shared interval, without annualization. Fixed weights presume rebalancing at every observed interval; fees and buy-and-hold drift are excluded.
Correlation describes this supplied sample and does not establish future diversification. All prices must use one quote currency. Raw CSV prices and filenames are excluded from saved scenarios and result exports.
Fewer than 30 aligned returns are available; this is a short sample.

Calculation breakdown
Asset A	Asset B	Aligned-return Pearson correlation · ratio	A interval sample volatility · %	B interval sample volatility · %
A	A	1	11.54700538	11.54700538
A	B	-1	11.54700538	11.54700538
B	A	-1	11.54700538	11.54700538
B	B	1	11.54700538	11.54700538

Saved scenarios

Save up to 20 new-tool scenarios on this device, separately from the six existing tools. Prices and balances stay out of the URL. DCA, journal and correlation scenarios save settings and a digest, requiring the matching CSV again to calculate.

Scenario nameSaved scenario

Saving requires browser storage and Web Locks.

Formula and worked example

Intersect all supplied price dates, then compute price_t / price_previous − 1 for each asset. Pearson correlation uses those aligned returns. Portfolio returns sum your fixed weights; volatility is sample standard deviation per aligned interval.

Synthetic A returns of +10%, −10%, +10% and opposite B returns have correlation −1. Equal weights give zero interval portfolio volatility, so the diversification ratio has no finite denominator. This small example does not establish future diversification.

These estimates use bounded decimal arithmetic. They are scenario calculations, not trading instructions or forecasts.

Methodology sources: NIST Pearson correlation