market cap9 May 2020 18:44
At its intraday peak, UKOG was valued in excess of £300m.
Today, it is valued at £21.2m.
The increase in the number of shares in issue helps to explain the decline of the share price. but has nothing to do with the decline of the market cap, (if assets remain the same, then shares in issue up, say, 100%, share price down 50%, market cap remains the same).
Of course, £300m+ was in different, more optimistic circumstances, but £21.2m? Just from the point of view of reasonableness, that looks to be exaggerated.