Why this usage doesn't seem right - "create speculation"

According to the Cambridge dictionary, this is the Financial English definition of "speculation"

the act of buying something hoping that its value will increase and then selling at this higher price in order to make a profit:

• speculation on/in sth Evidence that the economy is accelerating could fuel further speculation in commodity markets.
• The share issue coincided with a huge rise in amateur stock market speculation.

So yes, the word "speculation" can be used in this sense.

However, the original text does lack the expected fluidity for a small piece on financial market, since it is a bunch of short sentences. Here is a suggestion, alterations are in italics:

People speculate and trade in stock marketing. There have been cases of traders pumping money into a specific stock in order to create a fake demand for it which in turn shoots its price up, leading to further speculation.