Oil will be the centre of attention again today: yesterday the price of a barrel of Brent crude dipped below $68, a five-year low, before rallying to more than $72. As oil gyrated, so did Russia's currency: at one point on Monday the rouble was down 6.5% against the dollar, its worst drop since Russia's calamitous sovereign-debt crisis of 1998. Russia’s central bank will be watching oil prices nervously. A cheaper rouble makes imports, which include staples like meat, vegetable and dairy products, more expensive. This lifts inflation, which is already 8.4%, and eats into Russian consumers’ spending power. Cheap roubles also spell trouble for Russian firms, by making dollar-denominated debts harder to pay off. Russian companies have $130 billion to repay by the end of 2015 and, with around $30 billion due this month, will be scrambling for dollars. Unless oil bounces back, the rouble could drop more.