The thinnest line on the chart makes the mechanism visible: on August 27 the gap between what users paid in gas and what the chain kept was $20,396, and Cryptopolitan puts Ethereum data-posting costs at roughly $400 that day [6]; because Arbitrum's cut is 10% of net protocol revenue rather than of gross throughput [5], 10% of $200,211 less $400 is $19,981, and $19,981 plus $400 comes to $20,381, reconciling the reported spread to within about $15 [23]. That is the entire cost structure of an Orbit rollup at small volume, and it does not deteriorate much at large volume: 90.1 cents of every gross fee dollar stayed on the chain on September 2 [18]. Annualising a single day is a stretch nobody should really make, but the number that falls out is $1.46bn [19], and it is worth writing down anyway as a marker even though it will likely never arrive.
Who receives the cash is the more interesting version of the question. Arbitrum's ecosystem take on one day was roughly 25 times the fees Arbitrum One collected for itself [20], and at that daily rate the DAO and the Developer Guild are carrying a $135m annualised line they did not build [21].
The demand has one name and a short history: Pons, live 12 days after the July 1 mainnet [8], running a V2 that charges a launch fee and then collects swap fees twice, once on the bonding curve and again in the Uniswap v4 pool that graduating tokens land in [10]. Eighty percent of the V1 protocol cut buys and burns PONS, and the team said on August 29 that 29% of the original supply had been retired [11], with the token up more than 300% on the week to an all-time high near $0.50 according to CoinGecko [12]. Fees retire supply, which lifts the price, which in turn recruits the next launch. Uniswap is the other party getting paid: its v4 and v3 deployments on the chain took $2.68m and $1.45m over 24 hours and 81% of DEX volume [13], which is $4.13m, or 93% of what the chain itself charged on its record day [22], and the chain now clears 51% of all Uniswap v4 volume across every network Uniswap runs on [14].
Against $1.405bn of daily DEX volume and $2.707bn bridged in, tokenised real-world assets on the chain are worth $193.25m, about 7% of the bridged value [15][24]. The equities rail is still a minor part of that picture, not the headline.
None of this is Robinhood revenue in a form a shareholder can size, because CFO Shiv Verma told Q2 analysts the company earns a few basis points per transaction with roughly half shared with Arbitrum, and gave neither a rate nor a reconciliation [16].
This is probably wrong, but I read the $4m a day as at least half a pricing artefact rather than a business, since the gas sponsorship threshold in Robinhood's Wallet was cut from $5 to $0.50 and the program runs to September 29 [17], which is 27 days after the record [27]. I see it resolving one of three ways: fees hold at some fraction of the peak once users pay their own gas, which would make this a toll road with real traffic; or they track PONS lower, and it was a burn loop with a brokerage's name on it; or Robinhood files a reconciliation showing its own take is a rounding line, in which case the fee table has been measuring Arbitrum's revenue and Uniswap's, hosted by a broker. What would change my mind is chain revenue still above $1m a day in mid-October with PONS well off its high.
