How often prices refresh
When a coin is fetched
The ticker fetches a coin’s price and chart as that coin’s turn comes up in the rotation, and, in Two or Four per screen, as each page turns. The page puts it as Fresh prices and chart data are fetched as each coin's turn comes up. The ticker paces its own fetches; stepping through coins quickly with the remote buttons shows Too fast or Easing off under a price rather than hammering the server.
What “24h” means
Every 24-hour figure is rolling: always the last 24 hours counting back from this moment, not "since midnight". It refreshes with the coin’s fetch.