Seeing a negative total balance after adding an Exchange Connection? There could be many possible reasons for that.
Many exchanges have various restrictions on API connections. You can see some of them here. For example, Bittrex allows us to only import transactions that are less than 30 days old. Therefore, the portfolio value may be negative if transactions older than 30 days are not manually accounted for.
As our blog post mentions, funds that are being used need to be accounted for. For example, if you purchase 1 BTC on Coinbase for $9000 using a credit card, Delta will add a buy of 1 BTC / USD and deduct $9000 from USD (fiat) entry. You need to add a deposit of $9000 into the USD to match these funds.