The words, defined once

Most of the confusion in this market is vocabulary rather than mechanism. Two venues publish a funding rate and pay it on different things; two data vendors both say “historical” and mean a decade apart. Each entry says what the word means here, and what it changes about a purchase.

Funding ratealso funding, funding rates

A periodic payment between the two sides of a perpetual swap that holds its price near the index. Longs pay shorts when the rate is positive, shorts pay longs when it is negative, and the venue takes no cut. It is quoted per settlement interval, not per year, and the venue picks the interval — eight-hourly is the common convention and several settle hourly, so two quoted rates can be the same word and a different quantity.

OHLCValso candles, OHLC, candlestick data

OHLCV is a bar summarising trading over a fixed interval — open, high, low, close and volume — computed from a venue's trade prints rather than observed directly. Every candle is an aggregation, and the interval boundary, the timezone it aligns to, the trades included and the fields returned are all the publisher's choices. Two feeds labelled one-minute candles for the same pair are routinely different series.

Open interestalso OI

The number of derivative contracts open at a point in time — entered into and not yet closed, expired or settled. It counts positions outstanding rather than turnover, so a trade between two existing holders moves none of it while volume still rises. Every long is matched by a short, so there is one market-wide total and not two. Each venue reports it in units of its own choosing.

Rate limitalso rate limits, rate limiting

A rate limit is the ceiling a provider puts on how much of its API you may consume, and the unit it is counted in is the vendor's own choice — requests per second, calls per minute, weighted cost per minute, credits per month, or a counter that decays while you wait. Two limits quoted in different units cannot be compared, and the identity they are charged against differs as well.

Redistributionalso redistribution rights, redistribute

Redistribution is showing market data, or anything derived from it, to somebody outside your own organisation. Vendors licence it separately from the right to use the data internally, usually at a different price and often only by negotiation. Almost every free and entry-paid tier in this catalogue grants internal use and withholds redistribution, which is why a working prototype can still be unlicensed.

Taker feealso taker, taker fees

A taker fee is what a venue charges when your order executes immediately against something already resting on the book, rather than waiting there for somebody else. It is set by what the order did, not by what type it was, and it is usually the higher of the two rates a venue quotes. Most automated strategies pay it on most of their fills.

A term gets a URL here only when the catalogue uses it in at least four other pages and there is more to say than the definition. The rest are explained where they come up.