Just to add to cbew's comments:

It depends on exactly how the offer is structured. Assuming the simplest, that Teck makes an offer for all outstanding shares of CUU:

1. Teck makes an offer of say $4 a share to all CUU shareholders; the offer would also include an expected closing date.

2. CUU Board accepts the offer and recommends shareholders to accept offer.

3. The offer would require the approval of 2/3 majority of shareholders.

4. If the shareholders voted to accept, by the closing date, all shares would be acquired by Teck.

The offer would also include terms for all outstanding warrants, options etc. The offer may also include break up fees (fees that CUU has to pay Teck if the deal does not go through), and may include first right of refusal to match competing offers.

In this case, there is no date of record required. Whoever owns the shares before the closing date will have the shares acquired by Teck on the closing date. Normally, once the announcement is made the share price would jump to the offer price, in this case, about $4; sometimes the sp may jump to more than the offer price because investors may speculate that a higher competing offer may come, if the deal is good. It would be too late to try to buy the shares “cheap” once we have that announcement and that’s why one doesn’t want to be caught without the shares if one thinks an offer may come any date. JMO GLTA!