Despite the grim outlook during the COVID-19, banks were not in a position to just keep depositors' money in their vaults, they had to invest to generate profit. Therefore, many banks, especially in the US, decided to purchase government bonds to generate at least a small return while accepting little risk. This strategy was understandable, as it was probably the most conservative and straightforward alternative while facing a lack of appetite for capital from companies.
Once the lockdowns ended, the situation reverted. Inflation suddenly started to climb rapidly due to the enormous amount of money that central banks pumped into the economy, paired with the rise in energy prices due to the ongoing Russian- Ukraine war. The US recorded a 9.1% inflation rate in June 2022, the highest in forty years. The Eurozone hit the 10% mark in September 2022, its highest-ever recorded rate.
In the race to contain inflation, the central banks raised interest rates at record speed. The US Federal Reserve raised their interest rates from 0.25% to the current 5% in less than a year. The European Central Bank raised interest rates from 0 to 3.5% in under seven months. For both institutions, this represents the fastest rate of increase in their history.
While this made sense to stop rising inflation, it has caused other unwanted damage. For example, when a bond is issued at 2% interest per year, it is valued at 100% of its market value. If an identical bond is issued at a later date, giving the holder 4% interest, the first bond looks much less attractive. In that case, the first bondholder would have to accept a price reduction if the old bond is to be sold, as there is a better investment opportunity available.
A 1% increase, depending on the type of bond, may easily lead to a decline of 8% in the value of old bonds. Some commercial banks had stocked up on US government T-bonds, which represent very little risk, so long as the bonds are kept until they expire, returning the full investment capital plus interest. However, if depositors come demanding their deposits, as happened with Silicon Valley Bank in March, the bank will be forced to sell some assets, in this case at a large loss, to gain liquidity quickly.