MUMBAI, Sept. 4 -- Consumption stocks, which spiked after Prime Minister Narendra Modi flagged a goods and services tax (GST) cut in his 15 August Independence Day speech, extended gains on Thursday as the final tax slabs were unveiled.

At 1:19pm, the Nifty FMCG index was up 0.6% and the Nifty Consumption index 0.48%, both outpacing the Nifty 50, which rose 0.37%. Mahindra & Mahindra, Colgate-Palmolive (India), and Britannia were among the top performers on the consumption gauge.

Since 15 August, the Nifty FMCG index has climbed 4.4%, compared with a 0.7% rise in the Nifty 50. Analysts expect the rally to sustain, underpinned by robust volume growth that could feed into stronger earnings.

The impact, however, will not be confined to co...