KEI Industries fell about 8% to roughly ₹4,850–4,910 in Friday's session, the worst hit in a sector-wide slide. Polycab India dropped ~5–5.9% to about ₹8,300–8,350, RR Kabel fell up to 5%, Finolex Cables up to 5% and Havells about 2.7%. The stock that caused it barely moved: UltraTech Cement was flat to +0.6% around ₹11,325.

What actually happened

The Aditya Birla Group formally launched Ultravolt, a wires and cables business housed inside UltraTech Cement. The numbers behind it are the story: ₹1,800 crore of committed capex, of which roughly ₹890 crore was already spent as of June 2026, a plant at Jhagadia in Bharuch, Gujarat, and installed capacity going from about 1 million km to 3.5–4.0 million km. UltraTech says that makes it the second-largest wires player by capacity on day one, with a stated goal of a top-two spot in cables and wires within five years.

Nobody's quarter changed today. What changed is the terminal margin assumption — and this is a de-rating, not an earnings event.

The weapon isn't the ₹1,800 crore. It's the shelf.

Ultravolt starts with 5,000-plus UltraTech Building Solutions outlets and is targeting over 1 lakh retailers across 500+ districts and 6,000 pin codes, backed by 20+ warehouses. Those counters already sell cement to the same contractor who buys the house wire. The launch range is home wires and flexible wires — the retail dealer shelf, not the industrial EPC order book — which is precisely where Polycab and KEI spend to hold distribution.

That's why brokers moved their pencils. Nuvama now models a 150–250bp gross margin hit for incumbents, up from its earlier 100–150bp, citing aggressive pricing and higher channel investments. Jefferies puts the wires business at 3–7% of UltraTech's FY30 revenue and EBITDA once it scales. The fight shows up as dealer discounts, not lost tenders.

What would flip it

Nuvama still keeps Polycab and KEI as its preferred picks in the space, which tells you the sell-off is priced off a ramp that hasn't happened yet. The concrete thing to watch: UltraTech's Q2 FY27 disclosure in October — how much of the ₹1,800 crore is actually deployed and what revenue Ultravolt books — and whether the incumbents' own Q2 gross margins land inside Nuvama's 150–250bp band or blow through it. Slow ramp, and today's de-rating unwinds fast.

As of 4 Sep 2026, ~2:45 pm IST. Prices and percentages as reported intraday by the sources below; figures differ slightly by snapshot time. Sources: Business Standard, Business Today, India Infoline, Aditya Birla Group release. For discussion and education only — not investment advice. Verify before acting.