Short-selling data for one stock, newest first, in four sections: short_interest (FINRA short interest per settlement date since 2021: short_shares, prev_short_shares, change_shares, change_pct, avg_daily_volume, days_to_cover, dtc_capped), short_volume (FINRA daily off-exchange short volume, last two years: short_volume, short_exempt_volume, total_volume, short_volume_pct), fails_to_deliver (SEC fails-to-deliver, last two years: quantity, price, value_usd) and ats_weekly (FINRA weekly ATS and OTC volume since December 2021, per tier: ats_shares, ats_trades, otc_shares, otc_trades, ats_pct). Without dates: about the last year of short interest (24 settlement dates), the last 30 trading days of short volume and of fails-to-deliver, and the last 12 weeks of ATS data; with from and/or to, each section covers that range, up to 200 rows. Short interest (FINRA) is the number of shares sold short and not yet covered on a settlement date, reported twice a month about 8 business days after the settlement date. Daily short volume (FINRA Reg SHO) is something else: the shares sold short on one day among off-exchange trades only (not short interest, and not total market volume); short_volume_pct is not a sentiment indicator, because market makers' hedging short sales are normally around half of off-exchange volume. Fails-to-deliver (SEC) are shares not delivered on the settlement date, with the SEC's price (the previous close). ATS weekly (FINRA) is volume on alternative trading systems (dark pools) and other off-exchange (OTC) trading, published 2 to 4 weeks late; ats_pct is ATS divided by ATS plus OTC, not a share of total volume. There is no short interest as a percent of float or shares outstanding (no reliable float data). Share classes are separate tickers (BRK.A, BRK.B).