Answer: No, we will not invest money in this stock.
Step-by-step explanation: In the attached figure , the price p of the stock (Y-axis) is plotted against time t (X-axis). Let P(a,b) and Q(c,d) be any two points on the graph. Since the slope m is negative, so, we have

Since
, so, we must have

This implies that, as the time increases, the price of the stock decreases. Hence, it will be a loss investing money in this stock.
Thus, we will not invest money in the stock because there will be loss.