Question about Cash and Borrowing on Margin balance.

Good Morning!

I purchased 4 shares of BRK/B on August 3rd in a taxable brokerage account that has margin enabled.

Today on August 5th, the balances page shows:

Account total: $2142.13

Cash only current:$67.96

Cash and borrowing on margin current:$142.13

I was expecting the "Cash and borrowing on margin" to be close to 50% of the account total. What am I missing? Thanks!