The FTSE 100‘s rocketing as hopes of earnings-boosting interest rate cuts grow. With market confidence rapidly improving, London’s premier share index could be poised for further healthy gains in the days and weeks ahead. “London’s blue-chip index has powered higher, as a relief wave cascaded over markets amid hopes for earlier interest rate cuts in the US,” analyst Susannah Streeter of Hargreaves Lansdown noted. “The latest snapshot of the weakening labour market fired up stocks on Wall Street, and positive sentiment is washing over the FTSE 100, which passed the 8,200 mark for the first time” on Friday. Guessing how stock markets will move in the short term is difficult. But with inflation heading lower, and many UK shares looking dirt cheap, there’s a good chance the FTSE 100 will keep rising. I think these two blue-chip stocks could be among the biggest gainers in the weeks and months ahead. Here’s why. I think Aviva (LSE:AV.) shares could continue their recent ascent. The life insurance giant still looks dirt cheap, its shares trading on a forward price-to-earnings growth (PEG) ratio of 0.7. Any reading below 1 indicates that a stock is undervalued. On top of this, a 7.4% dividend yield...