Inflection point is an event that results in a significant change in the progress of a company, industry, sector, economy etc. After the initial business of the company has taken off, the promotoers may expect a more siginificant business which includes the number of customers or size of turn over that would make the business viable enough. To fund this, the additional capital required is called Inflection capital. The investors invest this capital after having done the evaluation of the business potential through testimonials of the paying customers.
Once the business has crossed the inflection point, there would be need of more and more customers and turn over, i.e. growth of the business. The amount may be big and may require investments by larger VC funds.