Form4insider filings, from the source

Analytics

Insider buy/sell ratios

Two honest ratios per trading day, computed from open-market filings only: how many buy filings per sale filing, and net dollars as a share of total dollars (+1 all buying, −1 all selling). No index overlay — that needs licensed market data.

1M3M6M1YAll data1138 trading days · 78,942 buys / 173,932 sales · $7401530.56B bought / $25472530.60B sold
Buy : sale filing-count ratio (1.0 = as many buys as sales)
0.02.04.06.08.001-0207-0701-0607-0801-0907-1201-1107-1601-16
Net dollars as a share of total dollars (+1 = all buying)
-1.0-0.50.00.51.001-0207-0701-0607-0801-0907-1201-1107-1601-16
Daily filing countsbuy filingssale filings
010020030040001-0207-0701-0607-0801-0907-1201-1107-1601-16
Daily open-market dollarsboughtsold
$0$5000000.0B$10000000.0B$15000000.0B$20000000.0B01-0207-0701-0607-0801-0907-1201-1107-1601-16

Insiders sell for many reasons (compensation, diversification, taxes) but buy for mostly one. The count ratio typically sits well below 1.0 — its changes are the signal, not its level. Days are trading-day buckets with the 4:00 pm ET cutoff.