I read some of the other posts on the SLW board and I don't want to respond over there because of the lack of civility.
One supposed answer for this massive exchange of shares is that SLW was added to the TSX index and a link was provided.
SLW has been a part of the TSX index since even before SLW started trading in the USA. And, re-balancing based on what I've seen in the past has never resulted in a price move like the one I saw on SLW's ticker. It was up 2% in 30 seconds.