Ann: Options Underwriting and Placement, page-25

ML would be aware of the Washability results at Issac river,through his other business associations.Any purchases,on-market,before the results are released could be viewed,rightly,as Insider Trading.
Conversely,an attempt to suppress the share price,may well prove costly should the results be positive.Other factors to consider would be an unexpected TO offer or JV arrangement proposal from a third party.
I think the larger players will re-enter the market,once the Washability results are announced.
Its a wait and see hiatus until then.