This graph precisely illustrates my point. Let's conservatively posit that a workable fusion reactor is worth $2 trillion; the world spends many multiples of this on energy each year. The cost of acquiring fusion, according to its advocates, is equal to the integral of any one of the curves on this graph, which looks to be on the order of ~$100b. This is well within the range of investment attainable by private sources, just look at pharma. In other words, if fusion advocates are to be believed, the market is failing to the tune of few trillion dollars, roughly the GDP of the United Kingdom, and has been for decades. Now, markets are not necessarily efficient, but is this a believable scenario? I claim no.