After a recent tarnishing, gold was shining again Thursday. The precious metal was taking its cue from the Bank of Japan's decision to start unraveling an ultra-easy monetary policy that has pumped liquidity into global financial markets for the past five years. The move is a prelude toward the central bank's ultimate goal of lifting interest rates, which remain near zero in Japan. The link between the BOJ's announcement and gold's rally sounds counterintuitive. The precious metal has benefited from a massive surge in global liquidity, as have other commodities. Besides the BOJ, the world's other major central banks -- the Federal Reserve and the European Central Bank -- had also kept interest rates at historically low levels for the past few years. This low-interest rate environment encouraged global borrowers to invest in higher-yielding assets at very low cost, boosting the price of everything from commodities to stocks and emerging-market bonds. This "asset inflation" has been a double benefit for gold, which not only rose as a commodity but also because it serves as a hedge against inflation. But global central banks have now recognized inflation pressures and have entered a tightening mode, with the BOJ just now joining the bandwagon. On the face of it, this is all bearish for gold but much of this has already been discounted by the market. Anticipation of the BOJ's move -- together with expectations of further rate hikes by the ECB and the Fed -- contributed to gold's recent correction from 25-year highs of $580 per ounce in late January to $540 this week. Other commodities have also fallen sharply, with the CRB index dropping over 9% since late January. A link between rising rates and commodities has been made by Jeffrey Frankel, economics professor at Harvard's Kennedy School of Government, as reported here .