Zimbabwe's key stock market index has risen almost 15% so far this week, defying the country's wider political and economic chaos.

The Zimbabwe Industrial Index has been defying gravity this year, rising more than 100% between May and November.

"There are strategic stocks which are gaining progressively every single day on the basis that there is nothing else to buy," Geoffrey Mhlanga, chairman of the Zimbabwe Stock Exchange, told the BBC's World Business Report.

Shares and property have become almost the only viable investment option with the money markets a non-starter, he explained.

With annual inflation running at nearly 150%, and with interest rates fixed at well below this level, investors are left with few other choices of where to put their money.

Stocking-up

In addition, some of the country's biggest companies are performing well, despite the fact that Zimbabwe is one of the fastest shrinking economies in the world.

The top 20 industrial firms have recently reported that profits are up by an average of 15% in US dollar terms.

Mr Mhlanga said that companies were managing to grow because consumer demand was strong, due to the fear of shortages ahead.

The runaway level of inflation also spurred both consumers and companies to buy sooner rather than later.

Budget blues

The only major dent in this year's stockmarket rally came after the November Budget.

The prospect of more tightly controlled markets caused stocks to plunge 30% in 10 trading days.

But this week has seen the rally re-emerge and start to win back the ground lost following the budget.

Despite the dramatic rises, the stock market is only keeping in line with inflation, meaning there are few real gains for people living in Zimbabwe.