It looks exactly like Robinhood (a liquidity issue), but without the faceless an unaccountable entity sitting behind them telling them to suspend trading.
These guys appear to be acting as middlemen between their New Zealand customers and several exchanges. Bank transfers take days to finalize (and weeks to settle), so their business appears to be built around capitalizing on that time opportunity and allowing their customers to lock-in quotes without having to wait for their funds to appear in their exchange account if they dealt directly with an exchange.
While the crypto markets are stable and the volume is predictable, everything is fine and they can maintain a balance on their exchanges and in their bank account. A sudden surge in volume (due to a massive price swing) means having to close shop and suspend trading while the transfer from exchange to bank account (or the other way) finalizes.