Spot Bitcoin exchange-traded fund issuers added another net 10,667 Bitcoin ( BTC ) to their crypto stacks as of their fifth trading day amid increasing trading volumes.

Data compiled by X account CC15Capital for Jan 17 shows that a net $440 million in Bitcoin was added to their holdings at the end of the day. BlackRock’s ETF accounted for most of this, with 8,700 BTC net gained — worth nearly $358 million.

The data also shows that nine ETFs (excluding Grayscale) have purchased nearly 68,500 BTC since their launch, currently worth around $2.8 billion.

The recent ETF-linked Bitcoin buys were partially offset by continued outflows from the Grayscale Bitcoin Trust (GBTC), which saw it sell 10,824 BTC — around $445 million worth. Nearly 38,000 BTC has left the GBTC since it was converted to a spot ETF on Jan. 11.

30,496 #Bitcoin was bought since ETF Launch.

Excluding $GBTC (selling driven by high fees vs others), the 9 ETFs bought 68,442 $BTC - a staggeringly large number.

Only 900 #Bitcoin is mined daily (dropping to 450/day in April)

— CC15Capital (@Capital15C) January 18, 2024

Meanwhile, data shared by Bloomberg ETF analyst Eric Balchunas highlighted the “Newborn Nine” — his nickname for the new spot Bitcoin ETFs excluding the GBTC — saw a 34% jump in daily volume as of the fifth-day trading.

This is interesting, the Newborn Nine actually saw a 34% jump in volume today vs yesterday. Normally with a hyped up launch you see volume steadily decrease each day post-launch, rare to see it reverse back up. All but one saw jump too but GBTC change flat so wasn't a volatility… pic.twitter.com/f6xOsLRWjr

— Eric Balchunas (@EricBalchunas) January 18, 2024

“Normally with a hyped-up launch you see volume steadily decrease each day post-launch, rare to see it reverse back up,” he added.

However, it should be noted that data around Bitcoin buying as reported by ETF managers are delayed compared to each fund’s transaction volume figures due to purchase settlement delays.

With investors piling into the new funds, the Bitcoin ETFs from BlackRock and Fidelity each tallied over $1 billion in assets under management at the close of trading on Jan. 18, per data from Bloomberg ETF analyst James Seyffart.

Day 5 #Bitcoin ETF Cointucky derby update. Waiting on data from $IBIT /BlackRock and $BRRR /Valkyrie. But $GBTC with another Big outflow -- $582 million. Total out of GBTC is $2.2 billion so far. pic.twitter.com/XxXfyJCA60

— James Seyffart (@JSeyff) January 19, 2024

Balchunas also noted that BlackRock and Fidelity’s Bitcoin ETFs are respectively in fourth and fifth position for weekly capital inflows across all U.S. ETFs. trailing only the Vanguard 500 Index Fund ETF (VOO), which aims to mirror returns of the SP 500 — the 500 largest public U.S. companies.

Another way to put the bitcoin ETF flows in ETF context (besides showing their #s relative to past new launches) is how they stack up to ALL ETFs in past 1 week flows. Even after four days two of them are in Top 5 and three in Top 10, up there w the studs $VOO , $QQQ et al. pic.twitter.com/oduhktEqwG

— Eric Balchunas (@EricBalchunas) January 18, 2024

CC15Capital also shared to X on Jan. 19 that Bitwise, so far, is the only asset manager to report its Jan. 18 Bitcoin holdings — which showed it adding another 491 BTC on the day.

“+$20,000,000 into BITB today,” Bitwise CEO Hunter Horsley wrote in a Jan. 18 X post. “Grateful for the trust to steward client’s assets.”

+$20,000,000 into BITB today.

Bitcoin purchased efficiently.

Now $390,000,000 in the last 5 days.

Grateful for the trust to steward client's assets.

[BITB disclosures prospectus: https://t.co/PhSsPpDY7h ]

— Hunter Horsley (@HHorsley) January 19, 2024

Bitcoin saw a less than 1% decrease over Jan. 17, but has seen an over $3.5% slide in the past 24 hours, per Cointelegraph markets Pro.