The filing for a mixed shelf offering and at-market offering prospectus by Nighthawk Biosciences indicates a potential increase in the company's capital, which could be used for growth and development. However, the introduction of additional shares into the market could lead to dilution of existing shares, typically resulting in a negative short-term impact on the stock price. The confidence in this analysis is high due to the direct correlation between share dilution and stock price, although the long-term effects may be positive if the capital is used effectively.