Regional assets invested in funds with an ESG tilt hit a record €1.1tn. Investors flocked to ESG funds last year. Once a fund is marked with a sustainable investment label, it makes it more accessible to some pension funds and other big investors that are looking for that label. However, there is no global consensus on what constitutes an ESG fund.

European Central Bank executive board member Fabio Panetta said a digital euro might be the innovation that sees negative interest rates passed directly to consumers. Panetta said officials keen to prevent bank runs could make the hoarding of digital central bank money unattractive by “penalizing remuneration” of holdings in excess of 3,000 euros.

Cryptocurrencies play almost no role in the staid world of corporate treasury, where protecting a company’s financial liquidity and cash reserves are key. Their massive volatility has ruled them out. Corporations invest their cash in very high quality, short-term fixed income securities, and are willing to accept a relatively low rate of return.

In Europe, investors looking to escape a sea of negative yields are snapping up some of the longest-maturity debt on offer in an attempt to park their money in assets that still provide some sort of return. On both sides of the Atlantic, the lengthiest debt is the focus of a debate over whether trillions of dollars of stimulus will trigger a resurgence in inflation.

About $1 trillion of bonds have seen their yields turn negative this week, meaning 27% of the world’s investment-grade debt is now sub-zero. Bond bulls got a boost on Thursday when the European Central Bank boosted its asset purchase program by an additional 500 billion euros in a bid to support the region’s economic recovery.

Collapsing trading volumes are a worrying sign for the market’s future. European Central Bank has taken its purchases of debt to unprecedented levels. By the end of 2021, investors will be even more squeezed out. The ECB is set to own around 43% of Germany’s notes. Trading volumes in bund futures have collapsed 62%.

Funds that buy US Treasury Inflation-Protected Securities recorded $1.8bn of inflows in the week ending Wednesday, the largest amount since June and the ninth consecutive week the funds have been allotted new money from clients. The inflows have been dominated by large institutions like endowments and pension funds.

In the case of governments, the link between green issuance and any additional green spending is tenuous at best. Germany, for example, identified €12.7 billion of eligible spending from last year’s budget – hardly an indication that the green Bund programme will be financing anything that was not already happening anyway.

Since 2016 the European Central Bank has adhered to the “market neutrality” principle, which aims to avoid distorting relative pricing of securities by only purchasing them in proportion to the overall eligible market. Mr Weidmann defended the principle and said: “It is not the task of the Eurosystem to penalise or promote certain industries.”

In March financial markets were subjected to their biggest stress test in more than a decade. Funds struggled to meet customer redemptions as buyers for credit products proved hard to find. Finland’s Ilmarinen Mutual Pension Insurance has classified corporate credit as illiquid. This is why regulators need to revisit rules covering daily redemptions.

The rapid growth of the green bond industry is fanning suspicions that some debt is environmentally friendly in name only, encouraging investors to ignore the (green) label and focus on the credentials of the issuer instead. “We don’t buy a bond because it’s green, but because the company is,” said Tom Chinery of Aviva Investors.

Banks are putting pressure on giant oil-and-gas companies to accelerate their renewable strategies. Credit Suisse has partnered with the Climate Bonds Initiative to accelerate the energy transition. The duo has established a pathway for companies to issue “transition bonds” as a bridge between their current business and greener offerings in the future.