Blockbuster job growth in the past several months has coincided with high-profile layoff announcements by a number of large companies.

So, how are both occurring at the same time? It’s not as contradictory as it might seem. Recent job cuts have been concentrated mainly in just a few sectors: technology, finance and media.

Relative to the U.S. labor force of 160 million people, layoffs so far have been dwarfed by consistently vigorous hiring — a monthly average of 248,000 jobs added over the past six months. The unemployment rate is still just 3.7%, barely above a 50-year low.

It turns out that many of the companies that are now shedding jobs had over-hired during the pandemic, when they thought the trends that emerged then — especially a surge in online shopping — would continue apace. As the economy has normalized, many of these companies have discovered that they no longer need so many employees and have responded with layoffs.