General Discussion, page-24

I'd hazard a guess that it was a lazy insto that needed to switch a small balance from cash to stock on the day.
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Otherwise, surely that same capital would have been better deployed on the TPD side of the ledger. Admittedly, TPD is far more illiquid, so you'd probably only have gotten half that amount by closing TPD up to .21 or .215, but that's still a discount after STX conversion, whilst STX is at .435.

if it were my capital, I'd have deployed to TPD.

a second theory is that it is someone seeking to buy the rumour and sell on the news, as may happen on the 22/12. If you did buy into TPD, your capital is possibly locked up past that date (unsure)...so maybe someone is doing a quick raid based on possible froth in the upcoming week. They may even be privy to draft policy etc.