Ann: Suspension from Official Quotation, page-13

Unfortunately there is only one reason for a suspension when the stock has this much momentum. I have seen this before. To stop the price from climbing further.

I think this gives credence to some of the theories around here. The IPO price has been decided already and it will be significantly lower than the current price to build interest. Possibly $150M MC is reasonable given current revenue. I've emailed the company and they have all but confirmed it with an uncommitted response.

This means that on release of the prospectus on Tuesday, the stock may experience a very sharp fall to near the IPO indicated MC. They have chosen to suspend it so that new buyers won't get burnt too hard.