A creation unit is the smallest quantity of ETF shares a fund will create or redeem at one time. Only an authorized participant can place the order, and it must deliver the full block rather than a partial amount. The contents exchanged for that block, whether cash or the underlying asset, are described by the fund's creation basket.
In US spot crypto ETFs, the process works in two directions. A creation adds shares to the trust when demand for the fund runs ahead of supply on the secondary market. A redemption retires shares when the reverse holds. Each completed transaction changes the fund's share count and its holdings of the underlying coin, which is the mechanism that links exchange trading back to the asset itself.
The block structure matters for anyone reading flow tables. Because shares move in whole units, daily creation and redemption totals arrive in steps rather than a smooth curve. A quiet session may show no change at all, not because interest disappeared but because activity never reached the size needed to trigger a unit. Readers comparing small day-to-day differences across funds should keep that granularity in mind, since issuers set unit sizes independently.
Creation units also sit behind the arbitrage that keeps an ETF's market price near the value of what it holds. When the fund trades above or below that value, an authorized participant can in principle create or redeem a block and capture the gap, which tends to pull the two figures back together. Persistent spreads are consistent with friction somewhere in that chain, such as limited participant capacity or constraints on moving the underlying asset.
InflowScan data reports flows in dollar terms, but those figures are derived from share movements that occur in these fixed increments. Treating the resulting series as a record of completed block transactions, rather than a continuous measure of sentiment, points to a more careful reading of short windows.