An extension to the term "hodl" that originated in December 2013 in Bitcoin forums, buidl is also misspelled on purpose from the word "build".
Generally used within cryptocurrency communities to indicate that work is being done to better the cryptocurrency space through new products and innovations.
gm is the short form writing for good morning. Used extensively within the crypto community where individuals greet each other casually. On the other hand, good night (gn) is used when people sign off for the day.