Since when do investors wait for a product to be sold before bidding up share price? Investing is always about anticipating the future. Otherwise, how do you account for the IPO and all of the secondaries? They didn't have a product and still the price was higher. Now that they have a product and are supposedly nearing the goal line, investors are ignoring the stock. Clearly the sentiment has changed.
This is not unique to ROSG. Check the history of DNDN. Price was at the high when their cancer drug was approved and since has lost 75% since approval and about 95% from the high.