Yeah because they would not be able to find a single fund manager to do an "immediate sale" (aka a direct offering) to. What is going to make the price spike higher? CEO announcing he is leaving? Nope, aside from small market fluctuations it is only going to get harder and harder to raise the funds the longer they wait. They were smart to do an ATM (relative to other current options) and would be smarter to start doing it as soon as possible while the momentum folks and hopeless longs are still on board. This is CLSN's only hope, there will be no news coming out in the near future to spike up the price.
With 40 million shares of trading volume in 1 day, they wil use an algorithim to ease the stock into the market in bits and pieces, AS NEEDED, most likely down the road whenever they have some good news that pops the stock. I don't think it's likely that they would sell today (although they could) since they have 27 million dollars cash in the bank, and the stock is at a 10 year low. On the conference call the CEO said they had cash to last them well into 2014. I think they set this up with Cantor Fitzgerald right away in the event that they mine the raw data and find some subset of data that is better than expected. Then they could sell into that pop and raise cash at a reasonable level. In retrospect, something they should have done already at higher prices.
Bear in mind this is a 25 million DOLLAR, shelf, not 25 million shares. At $3 it would be 8.3 million shares, at $1 it would be 25 million shares, same amount of money raised. Obviously they will use the money they have on hand and wait to see the data subsets and then access the shelf registration on good news, a litle bit at a time, IF necessary.
Also note, they are not obligated to use this shelf registration. They may never access it if it's not necessary.
Again, from the CEO during conference call, they have enough cash on hand to last "well into 2014"