World shares are set to post their best week of gains in six years after two consecutive weeks spent in the red, shrugging off a rise in global borrowing costs while the US dollar hit its lowest level since 2014.

The MSCI world index of stocks, which tracks shares in 47 countries, was up 0.4 per cent after European bourses opened on Friday. After suffering its biggest weekly drop since August 2015 last week, this week’s recovery puts the index on track for its best weekly showing since early December 2011.

The index has now reclaimed more than half of the 10.7 per cent plunge from a record intraday high on January 29 to a four-month intraday low a week ago.

Investors have been puzzled at this week’s quick rebound in stock markets, which has also coincided with a rise in bond yields on evidence that inflation is starting to creep up globally.

The argument most commonly offered by economists has been that historically, it’s not unusual for stocks and bond market borrowing costs to rise in tandem with a rapidly expanding economy.

“For me it’s really a question of maybe. Markets are taking a look at the inflationary outlook and saying OK, maybe rates are going up and maybe the economy will compensate for that,” said Michael Hewson, chief markets analyst at CMC Markets.

“That might change if we move to 3 per cent on the 10-year (Treasury).”

The global rise in borrowing costs has been led by the US 10-year Treasury, which hit a four-year high of 2.944 per cent this week. It last stood at 2.8932 per cent.

Yields across the euro area were mostly steady, although Germany’s benchmark bund yield was within sight of 2-1/2 year highs and set for its biggest weekly rise in eight weeks.

Investors were also watching for a sovereign debt rating on Greece from Fitch Ratings, set for release later in the day.

European shares were set to chalk up healthy weekly gains, snapping a three-week losing streak as earnings updates continued to impress, and volatility and jitters over rising inflation eased. Among country benchmarks, the UK’s FTSE was up 0.6 per cent and Germany’s DAX added 0.8 per cent, while Italy’s FTSE MIB outperformed, up 1.2 per cent.

MSCI’s broadest index of Asia-Pacific shares outside Japan rose 0.4 per cent, though many Asian markets were closed on Friday for the Lunar New year.

Japan’s Nikkei rose 1.2 per cent, with investors relieved to see the government appoint Bank of Japan Governor Haruhiko Kuroda for another term, suggesting the central bank will be in no rush to dial back its massive stimulus program.

The pan-European benchmark is up 3 per cent so far this week, set for its best week since December 2016, but still down around 6 per cent from the 2-1/2-year peak it hit in January.

Some put the rebound in equities down to investors being reassured by a fall in the VIX index – a measure of implied volatility on the S&P 500 index, also known as Wall Street’s “fear gauge”.

The index dropped below 20 for the first time since its spike to a 2-1/2-year high of 50.3 last week, a jump that caused massive losses among investors who bet equity markets would be stable on a combination of solid economic growth and moderate inflation.

Extending the previous day’s losses, the dollar’s index against a group of six major currencies fell to 88.253, the lowest since December 2014. The index was on track to lose around 2 per cent on the week in its largest decline since February 2016.

There is no strong consensus yet on what is driving the dollar’s persistent weakness, especially in light of rising yields. Some say it simply reflects a return of risk appetite and a shift to higher-yielding currencies, including many emerging market ones.

But others cite concerns that Washington might pursue a weak dollar strategy as well as talk that foreign central banks may be reallocating their reserves out of the dollar.

There are also worries President Donald Trump’s tax cuts and fiscal spending could stoke inflation and erode the value of the dollar.

“His protectionist policies could also fan inflation. Markets appear to have calmed down for now but fundamentally it is different from last year,” said Yoshinori Shigemi, global market strategist at JPMorgan Asset Management.

“You could say that right now, rather than stocks rising around the world, it is the dollar falling against almost everything,” he added.

Oil prices maintained this week’s gains, with U.S crude futures trading at $US61.74 per barrel, up 4.1 per cent so far this week. Brent crude traded at $US64.77

Elsewhere, virtual currency bitcoin recovered the $US10,000 mark for the first time in two weeks, gaining more than 70 per cent from its near three-month low of $US5,920.7.