e.g. Japanese components maker TDK Corp. (TDK) on Thursday said it will buy German electronic parts maker Epcos AG (EPCYY) in a deal valued at EUR1.4 billion as it seeks critical mass in a sector that's crowded but caught in a squeeze between falling prices and the slowing global economy. TDK shares fell 4.2% to $58.

A very important or crucial stage in a company's development, where the business activity acquires self-sustaining viability. When a company reaches critical mass, it is thought that they can remain viable without having to add any more investment.

This term is derived from nuclear physics, where critical mass is defined as the smallest mass of material that can sustain a nuclear reaction at a constant level. When compared to the financial definition, we see the similarities – being self-sustaining is the goal.