I believe the answer is: The flurry of investing artificially raised the price of stocks
The value of stock in speculative investing would be depended on the amount of people who buy the stocks rather than the company's performance in the market. This would give the impression that a price for a stock is higher than it supposed to be and weaken the stability in the stock market.
At this time in the Neolithic, c. 7000-6,000 B.C.E., people were often buried under the floors of homes, and in some cases their skulls were removed and covered with plaster in order to create very life-like faces, complete with shells inset for eyes and paint to imitate hair and moustaches.
No puedo verlo, Está borrosa
You may want to reword your answer. I did not understand the way you phrased it. Apologies. :l