RE: $1523 Sep 2021 08:30
"The Company has raised aggregate gross proceeds of $112,500,000, before deducting underwriting discounts and commissions."
they've sold all the ADS ($112,500,000 / $15 = 7.5m)
"Argo Blockchain has granted the underwriters a 30-day option to purchase up to an additional 1,125,000 ADSs at the public offering price, less underwriting discounts and commissions."
There may be a few more to come, which the brokers can still buy at $15 if they think they can make a profit from them.
i.e. none of the buyers are going to be selling their new shares at $15 on NASDAQ. If other shareholders choose to sell their existing shares at the IPO book price they are giving away free money, buy them :)