diff --git a/README.md b/README.md
index 8d4b123..27fc290 100644
--- a/README.md
+++ b/README.md
@@ -1,11 +1,13 @@
 # fs-cli-v4
 
-To run the project clone the reposistory and then run:
+To run the project clone the repository and then run:
 
 ```
 yarn
 ```
 
+## Setup
+
 Create a .env in the top level containing these keys:
 
 ```
@@ -14,12 +16,29 @@ ARBITRUM_RINKEBY_CHAINID=421611
 ARBITRUM_RINKEBY_RPC_URL=https://rinkeby.arbitrum.io/rpc
 ```
 
-To approve tokens run:
+You'll need to allow exchange to take the tokens from you:
+
+```
+yarn start approveTokens -n arbitrum_rinkeby \
+    --exchangeAddress 0x1B5A08020E94066a3fB91Aff8B395De2d9cfaDd2 \
+    --asset 100000 --stable 100000
+```
+
+Default unit for `asset` is `ether`, that is 18 digits after the dot.
+Default unit for `stable` is `6`, meaning 6 digits after the dot.  This
+matches the `USDC` format.
+
+You can see currently approved limits:
 
 ```
-yarn start approveTokens -n arbitrum_rinkeby -e 0x1B5A08020E94066a3fB91Aff8B395De2d9cfaDd2
+yarn start showAllowance -n arbitrum_rinkeby \
+    --exchangeAddress 0x1B5A08020E94066a3fB91Aff8B395De2d9cfaDd2
 ```
 
+Use `approveTokens` to update the exchange allowance.
+
+## Trade
+
 To trade:
 
 ```
@@ -32,6 +51,7 @@ To estimate a trade:
 yarn start estimateChangePosition -n arbitrum_rinkeby --exchangeAddress 0x1B5A08020E94066a3fB91Aff8B395De2d9cfaDd2 --deltaAsset <deltaAsset> --deltaStable <deltaStable>
 ```
 
+## Liquidations
 To liquidate:
 
 ```
diff --git a/src/index.ts b/src/index.ts
index ede17c9..759d50d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -186,38 +186,120 @@ const main = async () => {
     )
     .command(
       ["approveTokens"],
-      "approve_tokens",
-      async (yargs: Argv) => yargs,
+      "approve tokens to be used by the exchange",
+      async (yargs: Argv) => {
+        return yargs
+          .option("asset", {
+            alias: "a",
+            describe:
+              "the amount of asset you want to be accessible to the exchange",
+            type: "string",
+            default: ethers.utils.formatUnits("100000"),
+          })
+          .option("assetUnits", {
+            alias: "A",
+            describe: "units to use when parsing and showing the asset amounts",
+            type: "string",
+            default: "ether",
+          })
+          .option("stable", {
+            alias: "s",
+            describe:
+              "the amount of stable you want to be accessible to the exchange",
+            type: "string",
+            default: ethers.utils.formatUnits("100000"),
+          })
+          .option("stableUnits", {
+            alias: "S",
+            describe:
+              "units to use when parsing and showing the stable amounts",
+            type: "string",
+            default: "6",
+          });
+      },
       async (argv: any) => {
+        const {
+          asset: assetAmountRaw,
+          assetUnits,
+          stable: stableAmountRaw,
+          stableUnits,
+        } = argv;
+
+        const { formatUnits, parseUnits } = ethers.utils;
+
+        const assetAmount = parseUnits(assetAmountRaw, assetUnits);
+        const stableAmount = parseUnits(stableAmountRaw, stableUnits);
+
         const { accountNumber, networkId, exchangeAddress } =
           getStandardParams(argv);
 
         const wallet = loadAccount(networkId, accountNumber);
         const exchange = IExchange__factory.connect(exchangeAddress, wallet);
 
-        const assetTokenAddress = await exchange.assetToken();
-
-        const assetToken = IERC20__factory.connect(assetTokenAddress, wallet);
+        const approve = async (address, tokenName, amount, unit) => {
+          const token = IERC20__factory.connect(address, wallet);
+          const tx = await token.approve(exchangeAddress, amount);
+          await tx.wait();
+          const amountStr = formatUnits(amount, unit);
+          console.log(
+            `Approved ${amountStr} ${tokenName} tokens to be used by ${exchangeAddress}`
+          );
+        };
 
-        const tx1 = await assetToken.approve(
-          exchangeAddress,
-          ethers.utils.parseEther("100000")
+        await approve(
+          await exchange.assetToken(),
+          "asset",
+          assetAmount,
+          assetUnits
+        );
+        await approve(
+          await exchange.stableToken(),
+          "stable",
+          stableAmount,
+          stableUnits
         );
-        await tx1.wait();
+      }
+    )
+    .command(
+      ["showAllowance"],
+      "show token approved to be used by the exchange",
+      async (yargs: Argv) => {
+        return yargs
+          .option("assetUnits", {
+            alias: "A",
+            describe: "units to use when showing the asset amounts",
+            type: "string",
+            default: "ether",
+          })
+          .option("stableUnits", {
+            alias: "S",
+            describe: "units to use when showing the stable amounts",
+            type: "string",
+            default: "6",
+          });
+      },
+      async (argv: any) => {
+        const { formatUnits } = ethers.utils;
 
-        const stableTokenAddress = await exchange.stableToken();
+        const { assetUnits, stableUnits } = argv;
 
-        const stableToken = IERC20__factory.connect(stableTokenAddress, wallet);
+        const { accountNumber, networkId, exchangeAddress } =
+          getStandardParams(argv);
 
-        const tx2 = await stableToken.approve(
-          exchangeAddress,
-          ethers.utils.parseEther("100000")
-        );
-        await tx2.wait();
+        const wallet = loadAccount(networkId, accountNumber);
+        const exchange = IExchange__factory.connect(exchangeAddress, wallet);
 
-        console.log(
-          "Approved both tokens for account: " + (await wallet.getAddress())
-        );
+        const allowance = async (address, tokenName, unit) => {
+          const token = IERC20__factory.connect(address, wallet);
+          const amount = await token.allowance(wallet.address, exchangeAddress);
+          const amountStr = formatUnits(amount, unit);
+          console.log(
+            `Allowance for ${exchangeAddress} for ${tokenName}: ${amountStr}`
+          );
+        };
+
+        await allowance(await exchange.assetToken(), "asset", assetUnits);
+        await allowance(await exchange.stableToken(), "stable", stableUnits);
       }
     )
     .command(