I'm an investment advisor set up as a sole proprietorship. Sometimes clients pay my management fees by personal check and other times the brokerage firm/custodian just debits client accounts and credits my account. My question is, should I be receiving W-9/1099-misc. forms from clients for fees over $600 a year? Thanks in advance.

“Sometimes clients pay my management fees by personal check and other times the brokerage firm/custodian just debits client accounts and credits my account. “---->Your clients don't have to give you a 1099 if they paid you less than $600 for the year.However,if they paid more than $600, then yes, they're technically required to file the 1099. So, they (need to) must file a 1099-MISC for every individual to whom they paid certain types of miscellaneous income during the year. The IRS uses these forms to determine the tax liability of the payee,you, and you must use the form to complete your federal tax return on Sch C /Sch SE.They do not use 1099-MISC for personal payments to individuals.
“My question is, should I be receiving W-9/1099-misc. forms from clients for fees over $600 a year?”---> As described above;you, as an IC(UNLESS you are S-or C corp) , need to receive 1099 an dreport your SE income on SCh C/SE or on 1040.You do NOT rceive a W2.Form 1099 and all its variations are filed to report certain types of income. Form 1099-MISC is given to independent contractors to show income they were paid.