This fragment is quoted in Aristotle. Some commentators believe that Aristotle added the phrase τὰ ὄντα (existing things) as a gloss over Heraclitus's use of πάντα (all things). Robinson argues that if Heraclitus had spoken about 'reality' as τὰ ὄντα, he would have used ἐόντα (Ionic form of ὄντα) as he uses elsewhere. I find this argument convincing. It still could be that Aristotle is loosely paraphrasing a thought of Heraclitus.