The offer is 2 IGO shares for every 3 SIR shares, plus a 52 cent...

The offer is 2 IGO shares for every 3 SIR shares, plus a 52 cent per SIR share cash payment, plus you get 1 share of the demerger of S2 (Polar Bear) for every 2 SIR shares.

On todays closing price of IGO at $3.10, multiply that by 0.66, add .52 and you get the closing price of SIR with S2 for free (recently trading in SIR has included an 8 cent buffer, presumably what the market are pricing in as the value of S2 shares).