In some embodiments, the invention relates to crystalline solid forms, including hydrates, polymorphs, and salt forms, of (S)-4-(8-amino-3-(1-(but-2-ynoyl)pyrrolidin-2-yl)imidazo[1,5-a]pyrazin-1-yl)-N-(pyridin-2-yl)benzamide. In some embodiments, the invention relates to amorphous solid forms of (S)-4-(8-amino-3-(1-(but-2-ynoyl)pyrrolidin-2-yl)imidazo[1,5-a]pyrazin-1-yl)-N-(pyridin-2-yl)benzamide. In some embodiments, the invention also relates to pharmaceutical compositions containing the solid forms, and methods for treating conditions or disorders by administering to a subject a pharmaceutical composition that includes the forms, including pharmaceutical compositions and methods for overcoming the effects of acid reducing agents.