JPMorgan Chase has come up with a tongue-in-cheek name for a serious index to measure the impact of President Donald Trump’s tweets on financial markets.

Analysts have named it the “Volfefe Index” for the nonsensical word “covfefe” that Trump tweeted — and never explained — early in his presidency. The index was created with a number of intricate graphs based on minute tracking of the number — and the time — of Trump’s tweets, as well as the words he uses.

“Trade and monetary policy have become an increasing focus for the executive branch ... via this carefully scrutinized social media platform,” JPMorgan analysts wrote in their report, Bloomberg reported. “In response, a broad swath of assets from single-name stocks to macro products have found their price dynamics increasingly beholden to a handful of tweets from the commander-in-chief.”

Analysts found that Trump’s pertinent tweets almost immediately create a measurable fraction of volatility “spikes” for both two-year and five-year Treasury bills, CNBC reported.

“We find strong evidence that tweets have increasingly moved U.S. rates markets immediately after publication,” the JPMorgan report states.

The findings are a dramatic indication of Trump’s impact on the market. They also underscore why previous presidents generally avoid actions like attacking the Federal Reserve ― in part to avoid triggering market volatility.