That is certainly an interesting question. But there are other sources of non-public information about a company. Let us take, as a hypothetical, a law firm is poised to initiate an action against a corporation. The timing and nature of the filing to be made is known only to the principles of the law firm, and to clients and associates.
Would you be of the opinion that acting on this knowledge, in ANY manner which impacts the trading in the stock of the corporation would come under the umbrella of the insider information you cite?
There is a fifth dimension, beyond that which is known to man. It is a dimension as vast as space and as timeless as infinity.