Yes, profits and losses from stocks, options, and futures can be combined with each other for tax purposes. But different tax forms will need to be filled out.
For stocks, you would report your profits/losses on Form 8949. This is mentioned in the Instructions for Form 8949:
Enter all sales and exchanges of capital
assets, including stocks
For options (those that are not Section 1256 contracts), you would report your profits/losses on Form 8949. This is mentioned in the Instructions for Schedule D:
Gain or Loss From Options
Report on Form 8949 gain or loss from
the closing or expiration of an option
that is not a section 1256 contract but is
a capital asset in your hands
For futures (and options that are Section 1256 contracts), you would report your profits/losses on Form 6781 (Gains and Losses From Section 1256
Contracts and Straddles). According to that form, Section 1256 contracts include futures contracts and certain types of options:
A section 1256 contract is any:
• Regulated futures contract,
• Foreign currency contract,
• Nonequity option,
• Dealer equity option, or
• Dealer securities futures contract.
So for stocks, options, and futures transactions, you will be filling out Forms 8949 and 6781. Then you will put the totals from those forms onto Schedule D. As you can see from Schedule D, short-term profits/losses from Form 8949 are reported on lines 1b, 2, and 3, and profits/losses from Form 6781 are reported on line 4. On line 7, those totals are combined.
If you have long-term profits/losses from Form 8949, they are reported on lines 8b, 9, and 10, and added up in line 15.
Then lines 7 and 15 are combined in line 16, which is used to fill out Form 1040. So yes, profits/losses (both short-term and long-term) from stocks, options, and futures can be combined with each other.