Bridges played a vital part in bridging assets from mainnet to the L2 chain. Hop exchange was one of the more famous Decentralized Bridge Protocol. Rather than locking and unlocking assets in mainnet and minting and burning on the L2, Hop maintains liquidity on both sides of the chain to allow easy and smooth bridges, without any wait times.

As of now Hop supports 4 chains:

• Optimism - Chain ID 10
• Gnosis - Chain ID 100
• Polygon - Chain ID 137
• Arbitrum - Chain ID 42161

Hop also support 6 assets across the bridge:

• USDC
• USDT
• WETH
• WBTC
• DAI
• MATIC

Each asset has its own deposit vault, and the Function sendtoL2 is invoked with the necessary parameters, which include the amount of asset to be sent, the destination chain ID. When assets are sent across the bridge, a TransferSentToL2 event log is emitted.

From this event, we can find the user details, destination chain and amount of asset involved transferred. From the contract which emits this event log we can identify the asset in consideration. Aggregating these data, we can generate the metrics we require.

The contract addresses for the respective vaults are

• 0x22b1cbb8d98a01a3b71d034bb899775a76eb1cc2 - MATIC
• 0xb98454270065A31D71Bf635F6F7Ee6A518dFb849 - WBTC
• 0xb8901acB165ed027E32754E0FFe830802919727f - WETH
• 0x3d4Cc8A61c7528Fd86C55cfe061a78dCBA48EDd1 - DAI
• 0x3E4a3a4796d16c0Cd582C382691998f7c06420B6 - USDT
• 0x3666f603Cc164936C1b87e207F36BEBa4AC5f18a - USDC

The contract addresses for the respective vaults tokens are

• 0x7d1afa7b718fb893db30a3abc0cfc608aacfebb0 - MATIC
• 0x2260fac5e5542a773aa44fbcfedf7c193bc2c599 - WBTC
• 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2 - WETH
• 0x6b175474e89094c44da98b954eedeac495271d0f - DAI
• 0xdac17f958d2ee523a2206206994597c13d831ec7 - USDT
• 0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48 - USDC

Since the start of 2022, 34000 bridges have been made, transfering almost half a billion worth of assets from Ethereum to layer 2.

Now let us look at some metrics when aggregated by destination chain.

In terms of bridge transactions to the destination chain:

• Arbitrum is the more popular bridge destination.
• Polygon and Optimism have comparable volumes
• Seeing the daily data, we can see Arbitrum has higher transaction volume mainly due to consistent higher volumes, rather than concentrated peaks
• We can also see Optimism transactions increase over the past few days.

Plotting the USD volume of assets bridges

• Arbitrum is yet again the main destination chain
• Unlike the transaction volume, we can see that Arbitrum has comprehensively higher USD volume, when compared to other chains.
• Gnosis chain is the lest used in both cases.
• While Optimism transaction volume grew over the past few days, USD volume hasn't shown the same ferocity.

Now that the Destination chain winner is decided, lets see by tokens transferred.

• The winner in this case is very clear, atleast in terms of transaction volume, which is WETH
• 3 in every 4 bridges is a WETH bridge
• ETH being the mainnet native token, could be the reason for this.
• Moreover, L2s like Arbitrum and Optimism use ETH as their gas token too.
• Add to it that, most new tokens want liquidity against ETH and stablecoins.

In terms of USD volume bridges

• Yet again WETH or ETH is the most popular asset bridges
• USDC comes next
• The other assets don't make a significant volume
• This is mainly because, ETH is the native token on Ethereum and the token held my most users
• Moreover, ETH and USDC pairs are the most important for any Token on the Ethereum network
• Most of the wallet held value on Ethereum is held in ETH and USDC, hence L2 usually tend to unlock these and put these good use.