Markets are likely to open firm in view of positive global cues and hopes that the Federal Reserve will be less hawkish. Also, FIIs turning net buyers to the tune of Rs 3086 crore in yesterday’s trade may aid sentiment. However, negative catalysts like Skymet Weather predicting a bleak monsoon in India over the next 1 month coupled with China continuing to struggle on key retail sales and industrial production front could push investors into a caution mode and fuel selling going ahead. For Nifty, the make-or-break support is seen at 18553 mark, while any upward march is possible only once the index breaches its all-time high mark of 18,888 mark.