It recovered to 72 in 2009, but then dropped again until autumn 2010. After that, silver zoomed off again on the back of rising gold prices and ultimately peaked at an SGR near 32 in April 2011.

Today, the SGR ratio is again moving between 45 and 60. Currently, the ratio is hovering around 53, Scotiabank data shows. So how does one play this? The ratio favours silver. To reach the peak SGR of 45, silver has to rise fast even if gold remains static. Since gold prices are rising, the gap with silver is widening. This means silver still has plenty of room to jump and outpace gold's increase. Traders who swear by the ratio are, therefore, buying silver and selling gold because they believe silver will give them higher returns than the yellow metal, for now.

It is a bold move. Because going by the present demand and supply, there is no reason to expect silver to rake it in. Within India, there is no demand for silver jewellery and the market is dull, says bullion trader Prithviraj Kothari, president, Bombay Bullion Association. In the international market, there is no news of mine supply disruption to ignite the market while silver's industrial users are still in doldrums, says Lakshmi Iyer, head (fixed income and products) at Kotak Mutual Fund.

But technical traders love being contrarian. In their view, the ratio shows silver is cheap, relative to gold, which makes it a steal. With gold currently at the $1770 level, silver should be rightfully at $39 instead of the present $34.