“Shall” is a word that has certainly come to be replaced in the American English language by using the word “will” instead. Often saying “I shall” do something comes off as sounding pretentious or haughty so we replace it with the word “will”.
Things weren’t always this way as “shall” was, and still is by some, considered the proper word to use with first-person pronouns (i.e. I and we), whereas “will” is used in a second and third-person context (i.e. you, he, she, they). This would be the technically correct usage of the two words from a British English context, and commonly in a legal context.
The applicability to business and investing here comes down to legal contracts and stated obligations of different parties. “Shall” used to be commonly integrated in legal documents but this has started to decline as it is commonly misused and can create some legal ambiguity. Consider the statement, “The property shall be cleaned by the lessee at the end of the lease term.” In a legal context the “shall” here places the actual legal obligation on the property in that “The property has a duty to be cleaned by the lessee at the end of the lease term.” No legal obligation now applies to the lessee to do anything at the end of the lease. Replacing this with “will” clears up the legal ambiguity, hence the movement away from using shall in a legal context.
Keep an eye out for the use of the word “shall” in any legal documents that you become party to as the position of the word can result in your contract technically meaning something else than you thought it would.