Roger Montgomery report on Vocus, page-73

Now that the SP has appreciated close to the bid value, from here we can say that the shares are 'more risky'. By that we mean SP can either go up or down rapidly in a just few days, with best estimates being roughly even chances. If you don't like high risk shares you can exit now for a pretty fair price given the short term outlook - sell. If you like risk and believe another offer is likely - buy.

@BertSmith 's post is good and indicative of the fact that nobody is particularly sure what will happen from here. But as Bert mentions, if you bought in because you thought the long term potential of VOC was good value for the price, then by holding you have the best chance of realising that potential - hold. The SP may well fall back down in the short term but the worst that can happen, from this bullish long term outlook is that you receive $3.50 or a higher offer.

In the short term, if another offer is forthcoming, the SP will go a bit higher and if accepted that will be the most you get. If the offer/s are rejected or withdrawn, the SP will crash down again, but you get the chance to realise the companies long term value (or possible lack of it!). But by sell or hold decision depends on you, especially in these situations where the future value has become more risky.