Negative-yield debt issuances became increasingly popular in 2015 when the amount of debt issued rose to more than $3 trillion, from $773 billion the year before. Issues reached their peak in 2016 at $4.9 trillion before slowly receding in subsequent years. But declines don't suggest the trend is over — so far in 2019 about $1.7 trillion has been issued.
Through the next seven months, issuers, primarily governments, will pay back $1.3 trillion and about $3.2 trillion in 2020 and beyond. Japan has been the primary issuer of the debt, issuing about $14 trillion since 2014, followed by the eurozone, issuing $4.3 trillion since then.
The bonds have a typically short maturity, or mature on average 1.3 years after issue, and essentially ask investors to pay to lend their money to the issuer. The appeal to investors is primarily twofold: The first is as bond yields fall, these holdings only increase in price, and the second follows the logic that the negative yields will still leave investors in a better place than equities.