RE: warrants$11.05 stems from the fact that $6.00 and 1 warrant used to get you a share of Northern Orion Resources. After the takeover, Yamana converted the terms of the warrant over to Yamana stock under the ratios negotiated in the deal. Since they negotiated 0.543:1 for the share conversion, the same number applied to the warrants.
So if I had 1000 shares of NNO, I ended up with 543 shares of Yamana after the takeover.
If I had 1000 wt.c's, I could pay $6000 and receive 1000 shares of NNO (before the TO), which would convert to 543 YRI after the merger. ($6000/543 shares = $11.05/share).
Similarly, now that NNO no longer exists, you might see people talking about 1.84 wt.c's per share of YRI. That's simply the NNO:YRI conversion (1/0.543 = 1.84).
Does that help?
Cheers,
mas75