Funding is exchanged at fixed intervals, and venues do not agree on the interval. Eight hours is the common convention, meaning three payments a day at set times; some venues settle every four hours, some every hour.
A rate quoted per interval therefore is not comparable across venues without normalising. The same printed number over one hour is eight times the cost of that number over eight hours.
Two ways to be wrong
The first is comparing a raw rate between venues on different schedules, and concluding one is far more expensive when it is simply quoted over a longer period.
The second is annualising carelessly. Turning a per-interval rate into a headline yearly figure means multiplying by the number of intervals in a year, and using the wrong interval count produces a number that is off by a large multiple while looking entirely authoritative. An annualised funding figure with no stated interval is not a figure at all.
Why frequency itself matters
Beyond arithmetic, the interval changes behaviour. Frequent settlement means positioning pressure applies continuously and a crowded lean gets corrected sooner. Eight-hour settlement lets a position build between payments, which concentrates the incentive to close right before a payment and produces the small, recognisable flurries of activity around funding timestamps.
For a short-term trader that timing is not trivia: a position held across a settlement pays, and one closed just before it does not, for an otherwise identical trade.
The reporting rule
State the interval alongside every rate, or state the rate already normalised and say to what. Anything else invites the reader to compare two numbers that are not measured in the same units — and since funding should be kept per venue anyway, the interval belongs beside the venue as part of its identity.