And so it begins: Taxes in the world's wealthiest countries are rising. Inevitable perhaps given the unprecedented COVID-19-era debt surge and, according to some investors, even a good thing if it helps close wealth gaps that the pandemic exacerbated.

Tax rises grabbed headlines recently when Britain, last year's biggest major borrower relative to gross domestic product (GDP), upped taxes on workers and employers, potentially raising 12 billion pounds ($17 billion) a year.

U.S. markets are edgy too after Democrats proposed raising tax rates on companies and those with annual incomes above $400,000.