There’s a ton of money flowing into HR technology companies this year. Of course, there was the half-billion that Zenefits picked up. But there was also $92 million for Virgin Pulse, $70 million for Glassdoor, $65 million for Udemy, and $45 million for HireVue. We hear talk of even more transactions on this scale in the coming days and weeks.

Last week, I remembered a poem I love by William Butler Yeats. “The Second Coming” is a work of dark genius. Here is the first verse of the poem:

Economics is all about supply and demand. (Technically, it’s all about the production, distribution, and consumption of goods and services.) But hey — I’m a marketer, not an economist.