Domestic equity bourses are likely to struggle in early Thursday trades amid weakness in SGX Nifty after US markets closed mixed overnight. Although the Fed left rates unchanged, it has kept the window open for another 50 bps hike in key rates for the year in case inflation remains sticky, which could probably spoil the party for investors who were hoping for a more dovish comment. With uncertainty over policy rates hanging around, the market may remain choppy with strong bouts of intra-day volatility, even as selective buying would continue as an ongoing theme. Technically, the markets may rally only above the all-time high level of 18888, while the make-or-break support for Nifty is seen at the 18553 mark.