The battery metals and flexible grid solutions company said the pair of investors were selling 7.79mln shares in a block trade.
YA and Riverfort will revert back to the agreed lock-in conditions for the balance of 18.2mln shares, meaning they are not available to trade until June 2020.
Under the terms of this agreement, all of these shares will be locked in until the end of next month, with 70% to be locked up through June and 40% of the total will be locked in through to the end of the year when the agreement will expire.
Red Rock received shares in December in exchange for £146,000 worth of obligations.
This was alongside a refinancing and share consolidation as James Parsons took over as Regency’s executive chairman, with a placing conducted to raise £831,000 and Parsons’ part-owned C4 Energy vehicle granted an option to acquire Regency's debt.