It is surprising to me that litecoin only raised in value 62% and that bitcoin won an even greater percentage, I really thought that LTC would have won a lot more money in May than what it won especially taking into account segwit got activated.
Yes Litecoin has been rising in the middle of the month and at the end it sligthly dropped so that is why the result is not as good as it seemed. Personally LTC should be winner of the month considering it was thought to be dead by majority of the community and after severeal months of consolidation it finally rose from the dead. However, the rank considers percentage change at the very end of the month