HONG KONG (BLOOMBERG) - Noble Group Ltd. founder and Chairman Richard Elman, with more than five decades of experience in commodities, said that you simply can't tell when raw material markets are turning, evoking wartime British prime minister Winston Churchill to help make his point.

"We all know commodities are cyclical, but predicting when that turning point comes is only possible with hindsight, especially with such excessive moves," Mr Elman said in the company's annual report, which was received on Tuesday. "Those who come hoping for some kernel of wisdom leave disappointed when I tell them that I don't know how all the different factors will play out - nor does anyone else."

Raw materials have rebounded from multiyear lows this quarter amid speculation that production cuts may diminish gluts of crude oil and metals. The revival, also buoyed by a weaker dollar, has helped to spur Noble Group's shares, which were battered last year as the trader posted a loss for the first time in almost two decades and had its credit rating cut to junk. Mr Elman offered a warning in the report to investors now buying in.

"There are those entering the business who think of us as some counter-cyclical play," he wrote. "But I'd just like to remind them that, while this is a great industry, and Noble is a great business, right now, as Sir Winston Churchill said at the outset of the Second World War, 'I have nothing to offer but blood, toil, tears and sweat'."

Noble Group rallied as much as 8.9 per cent to 49 Singapore cents, the highest since Nov. 12, and traded at 48.5 cents at 3:30 p.m. in Singapore. The shares collapsed 65 per cent last year, the biggest loser on the Straits Times Index in 2015, as the company battled the commodity rout and fended off attacks on the integrity of its accounting. The stock was removed from the STI this month.

Noble Group Chief Executive Officer Yusuf Alireza strove to turn around the company's fortunes last year, selling assets to raise cash including the remaining 49 percent stake in Noble Agri Ltd., boosting transparency and taking writedowns.

Mr Elman, the largest shareholder, raised his holdings in January, about a week before the stock bottomed at 26.5 cents in intraday trade.

"It was heart-wrenching to dispose of our entire Agri stake.....but it was the best course of action," Elman wrote. "We have to be smaller and we have to be more nimble. By extracting $5 billion in cash in recent years from the disposal of some of our interests, we have made good progress."

The shares have advanced this month, nearing their 200-day moving average, amid speculation Noble Group will soon be able to refinance some bank borrowings. In the report, the company - which trades energy and iron ore - said that the directors were confident in group's ability to refinance bank debt as it comes due in 2016.

Commodities plunged 25 per cent in 2015 as supplies overwhelmed demand in markets from crude oil to metals. The losses were driven by the weakest economic growth in China in a generation as the largest user shifted toward a consumer-led expansion and away from investment and infrastructure.

Last year, "must surely go down as one of the most challenging years that the commodity markets have had to endure for many decades," Mr Alireza wrote."These cyclical factors, which surely must balance themselves at some future stage, have been further compounded by structural changes in markets, principally caused by a moderation of the strong infrastructure spend in China."