How ETF Creation and Redemption Dey Work

ETF creation and redemption na the wholesale layer for fund business. Na primary market where small number of big trading firms give fund one basket of stocks and collect block of new ETF shares in return. Or dem give back the shares and collect the stocks. Retail orders no dey enter there.

That loop dey run under the ticker throughout the day. Na the mechanism wey dey keep ETF price close to the value of wetin the fund own.

Wetin be ETF creation and redemption?

An authorized participant, or AP, na big broker-dealer wey sign agreement to transact directly with the fund. Nobody else fit do am. The unit for this business na creation unit: one block of ETF shares, normally tens of thousands of shares, wey fund issue or cancel for one transaction.

Creation dey happen for four steps.

1. Fund publish the creation basket before market open. Na the exact list of securities and cash wey e go accept that day.
2. AP buy those securities for open market.
3. AP deliver the basket give fund, then receive one creation unit of newly issued ETF shares.
4. AP sell those shares for the exchange, or keep dem for inventory.

Redemption na the same trade but dem run am backward. AP hand one creation unit of ETF shares back to the fund, receive the basket of securities, and fund cancel those ETF shares. Shares outstanding dey rise and fall like this throughout the day. Na this be the first major difference between ETF and closed-end fund wey get fixed share count.

Why the loop dey hold price near NAV

Net asset value, or NAV, na the value per share of everything wey the fund hold. Market price na the price wey buyers and sellers agree on. E fit dey above NAV, wey be premium, or below am, wey be discount.

Na that gap dey pay the AP. If ETF dey trade above the value of its basket, AP fit buy the basket, deliver am, then sell the newly issued shares for the higher price and keep the difference. If ETF dey below the basket, AP go do the reverse: buy the cheap ETF shares, redeem dem for the basket, then sell the basket. Either way, AP dey sell the side wey cost more and buy the cheaper side. The two prices go move closer as the trade dey work.

Nobody need predict market direction correctly before this trade fit pay. Na spread capture be this. E fit repeat throughout the trading day, and na the practical limit on how far price fit move away from NAV. Our note on ETF premium and discount to NAV dey measure how tight that band dey in practice.

Why average daily volume dey understate ETF liquidity

Na this part most readers come for. An ETF own average daily volume dey measure how often people dey exchange the shares. E no dey measure how much size the fund fit absorb. Na the basket dey do the absorbing: if market maker fit buy the underlying stocks quickly and cheaply, e go quote the ETF with tight spread, whether the fund dey turn over ten million shares per day or ten thousand.

The panel below quote 5 US listed ETFs during the same midday hour on Wednesday, June 17, 2026. E rank dem by average quoted bid ask spread for basis points. One basis point na one hundredth of one percentage point. A 2 bps spread on a $100 fund na two cents wide.

WITH
    quoted AS
    (
        SELECT
            ticker,
            round(10000 * avg(2 * toFloat64(ask_price - bid_price) / toFloat64(ask_price + bid_price)), 2) AS spread_bps
        FROM global_markets.cache_stocks_quotes
        WHERE ticker IN ('SPY', 'VOO', 'VV', 'SPLG', 'IWC', 'EPHE')
          AND sip_timestamp >= '2026-06-17 15:00:00'
          AND sip_timestamp <  '2026-06-17 16:00:00'
          AND bid_price > 0
          AND ask_price > bid_price
        GROUP BY ticker
    ),
    traded AS
    (
        SELECT
            ticker,
            formatReadableQuantity(round(avg(volume))) AS avg_daily_shares
        FROM global_markets.stocks_daily_aggs
        WHERE ticker IN ('SPY', 'VOO', 'VV', 'SPLG', 'IWC', 'EPHE')
          AND date >= '2026-03-17'
          AND date <  '2026-06-18'
        GROUP BY ticker
    )
SELECT
    q.ticker           AS ticker,
    q.spread_bps       AS spread_bps,
    t.avg_daily_shares AS avg_daily_shares
FROM quoted AS q
INNER JOIN traded AS t ON t.ticker = q.ticker
ORDER BY q.spread_bps ASC

The tightest quote belong to SPY at 0.29 bps, with 64.43 million shares per day over the previous three months. The widest one na IWC at 30.89 bps, with 131.11 thousand shares. The two funds for the wide end hold securities wey AP dey take more time and money to buy. One hold micro-cap US names, while the other hold Philippine listings for exchange wey dey close hours before New York open. All the funds for the tight end hold the same deep pool of large US companies. Their share counts differ by very large multiples, but their spreads no differ the same way.

Make we take fund wey e tape dey show twenty thousand shares on normal day. Buyer wey want fifty thousand shares no need wait make sellers show. Market maker fit sell the block, buy the underlying stocks, and deliver those stocks to the fund for creation unit. The size come from the underlying market. The fund own volume history no enter the calculation at all. Na so market makers fit quote real size for fund wey almost nobody dey trade.

How big creation unit be compared with tape?

Most prints wey dey show for ETF tape small. Panel below sort one complete trading session of SPY prints into different size buckets, then measure the share of the day’s trades and shares wey each bucket carry.

WITH
    tape AS
    (
        SELECT size
        FROM global_markets.stocks_trades
        WHERE ticker = 'SPY'
          AND sip_timestamp >= '2026-06-17 13:30:00'
          AND sip_timestamp <  '2026-06-17 20:00:00'
          AND size > 0
    ),
    day_total AS
    (
        SELECT
            sum(size) AS all_shares,
            count()   AS all_prints
        FROM tape
    )
SELECT
    multiIf(t.size < 100,   '1 to 99',
            t.size < 1000,  '100 to 999',
            t.size < 10000, '1,000 to 9,999',
                            '10,000 and up')        AS bucket,
    count()                                         AS trade_count,
    round(100 * count() / any(d.all_prints), 2)     AS pct_of_prints,
    round(100 * sum(t.size) / any(d.all_shares), 2) AS pct_of_volume
FROM tape AS t
CROSS JOIN day_total AS d
GROUP BY bucket
ORDER BY min(t.size)

The 1 to 99 bucket make up 83.01% of the session’s prints and 34.17% of its shares: odd lots dominate print count and still carry sizeable part of the volume. The 10,000 and up bucket, territory for block trade, go the other way: 0.01% of the prints carry 18% of the shares. Creation unit dey the top of that range or above am, and e no dey ever show for this tape. Primary market transactions print to the fund, no be to the exchange. Na why one day’s tape dey understate how many shares really change hands.

Wey the mechanism dey strain

The loop no free and e no happen instantly. Na AP cost to assemble or unwind the basket dey create the cost. The ETF quoted spread carry that cost.

The first place to watch na the opening minutes. The panel below dey track quoted spreads with five-minute interval through one session. E show one large-cap fund and one micro-cap fund side by side.

SELECT
    formatDateTime(toStartOfInterval(toTimeZone(sip_timestamp, 'America/New_York'), INTERVAL 5 MINUTE), '%H:%i') AS et_time,
    round(10000 * avgIf(2 * toFloat64(ask_price - bid_price) / toFloat64(ask_price + bid_price), ticker = 'VOO'), 2) AS voo_spread_bps,
    round(10000 * avgIf(2 * toFloat64(ask_price - bid_price) / toFloat64(ask_price + bid_price), ticker = 'IWC'), 2) AS iwc_spread_bps
FROM global_markets.cache_stocks_quotes
WHERE ticker IN ('VOO', 'IWC')
  AND sip_timestamp >= '2026-06-17 13:00:00'
  AND sip_timestamp <  '2026-06-17 21:00:00'
  AND bid_price > 0
  AND ask_price > bid_price
GROUP BY et_time
HAVING countIf(ticker = 'VOO') >= 50 AND countIf(ticker = 'IWC') >= 50
ORDER BY et_time

For 09:30, the micro-cap fund quoted 54.65 bps, compared with 0.55 bps for the large-cap fund. The window start before opening bell and end after closing bell. Both ends of the panel dey outside the hours when the underlying names dey quote most actively. For the last bucket, at 16:00, the micro-cap fund quoted 271.06 bps, compared with 1.36 bps. The gap between the two funds na the basket showing inside the quote. A micro-cap basket fit hold many hundreds of names. Until each one don print, market maker dey price a basket wey e never fit value precisely. The same pattern dey show across the market. We explain am for why spreads dey widen for the open.

Credit na the harder case. Corporate bonds and high yield bonds no dey trade for continuous exchange. During a stressed week, many individual bonds no dey trade at all. AP wey no fit buy the basket at a price e fit know no go create ETF at a price e fit know. The panel below measure the average daily high-to-low range of the high yield bond ETF HYG, month by month, from late 2019 through the first half of 2020.

SELECT
    formatDateTime(toStartOfMonth(date), '%b %Y')                             AS period,
    round(avg(100 * (toFloat64(high) - toFloat64(low)) / toFloat64(open)), 2) AS avg_day_range_pct,
    round(avg(volume) / 1000000, 1)                                          AS avg_daily_volume_millions
FROM global_markets.stocks_daily_aggs
WHERE ticker = 'HYG'
  AND date >= '2019-10-01'
  AND date <  '2020-07-01'
GROUP BY period
ORDER BY min(date)

For Oct 2019, the fund average daily range measure 0.24%, with 17.4 million shares traded per day. For Mar 2020, the average range measure 2.9%, with 56.6 million shares traded. For conditions like this, discount wey normally close within minutes fit remain open for days. The arbitrage still dey exist, but the cost don high well. ETF dey print for where dealers go actually transact, instead of where stale bond mark put NAV.

A third case no need crisis. If local holiday close the fund underlying market, or if fund suspend creations, AP side of the loop no dey available for some time. Price then dey follow supply and demand. Funds wey hold options instead of shares, like the covered call ETFs, carry similar friction. The basket include contracts wey AP must price and hedge.

Wetin make this different from mutual fund?

Mutual fund no get secondary market and e no get AP. You buy from the fund and sell back to the fund at one price per day. Na the NAV wey dem strike after market close. The fund raise cash by selling securities when redemption requests enter. No intraday price dey for arbitrage. Na why mutual fund no dey trade at premium or discount. E also mean say every redemption go reach the portfolio itself. Our comparison of mutual funds versus ETFs explain the tax and cost trade-offs, while how mutual fund NAV is calculated show how dem dey determine the daily strike.

FAQ

Na who fit create or redeem ETF shares?

Na only authorized participant, meaning big broker-dealer wey don sign agreement with the fund, fit do am. Individual investors and ordinary brokers no fit. Everybody else dey buy and sell existing shares for exchange.

How many shares dey inside one creation unit?

Usually tens of thousands. The fund prospectus set the number, and e dey fixed for that fund. The dollar value of one unit dey reach well into millions. Na part of why institutions dey control the primary market.

Low average daily volume mean say ETF no liquid?

No be by itself. The tradable size of fund dey come from the securities wey e hold. So, if the basket liquid, fund fit fill order many times its normal daily volume with tight spread. Na thin basket be the real limit.

Wetin dey stop ETF price from moving far from NAV?

Na create-and-redeem arbitrage. Premium go invite AP to create new shares and sell dem. Discount go invite am to buy shares and redeem dem. Both trades dey pull the two prices back together. The gap dey widen when the basket hard to trade.

When premiums and discounts dey last?

When AP no fit work the basket. Closed foreign market, stressed credit market where the underlying bonds hardly dey trade, capacity limit for the strategy, or suspension of creations fit each keep the loop open longer than the few minutes wey equity fund gap usually dey survive.

Every panel here come with the SQL wey produce am. Open one, replace am with fund wey you dey follow, then run the same measurement for that ticker on Strasmore terminal.