Analysts at JPMorgan Chase & Co have created an index to measure the impact of US President Donald Trump's tweets. The index has been cleverly named "Volfefe Index" after Trump's mysterious "covfefe" tweet in May 2017.

The bank suggests that his love for the social media handle to express his thoughts and decisions have had a statistically significant impact on US Treasury bond yields, with two and five-year rates more impacted than 10-year securities.

The analysts found that tweets with words like "China," "billion," "products," "Democrats" and "great" are most likely to affect the prices.

According to JP Morgan's analysis report, the president has averaged roughly 10 tweets a day since the start of 2016, with 10,000 tweets occurring after his inauguration in 2017. His twitter activity has increased substantially since late 2018 with his highest number of tweets in the past four years occurring in recent months.

According to a Bloomberg report, Citigroup Inc.'s foreign exchange team feels that Trump's twitter activity is becoming increasingly relevant to foreign exchange moves. It found that his tweets generally followed a stretch of volatility across global currency markets.

The strategists at the bank said that about 10 percent of the American president's tweets since he took office in November 2016 pertain to subjects of importance to US markets. In recent weeks they've become increasingly centred on the dollar and the Federal Reserve.

Trump has made direct references to the Federal Reserve 20 times over the past month and that does not include his 23 August tweet questioning whether Chairman Jerome Powell was a bigger enemy than Chinese President Xi Jinping.