Ways to monitoring BTC trading profit and loss? Does anyone have recommendations when it comes to monitoring BTC trading profit and loss? I find it confusing when taking into account the transaction fee the exchanges impose (ie- GDAX). I use Coinigy for charts and entering orders.
No need for fancy scripts and databases:

[what you put in] - [what you got out] = [your profit]

All you need to know:


the price of BTC at the beginning of the period
the price of BTC at the end of the period
have a list of all USD deposits/withdrawals
have a list of all BTC deposits/withdrawals (and the value of BTC in USD at that moment the deposit or withdrawal was made)


I will try to explain with an example:


Starting balance = $0 + 1 BTC 
Deposit $1,000 (balance = $1,000 + 1 BTC)
Buy 1 BTC @ $900/BTC 1% fee = 0.01 BTC (balance = $100 + 1.99 BTC)
Sell 0.5 BTC @ $920/BTC 1% fee = $46 (balance = $555.40 + 1.49 BTC)
Withdraw $500 (balance = $55.40 + 1.49 BTC)


For a certain period in time the profit

= ([value of all assets at end of period] – [value of all assets at beginning of period]) + ([value of assets withdrawn] – [value of assets deposited])
= (($55.40 + 1.49BTC) - ($0 + 1BTC)) + (($500 + 0BTC) - ($1,000 + 0BTC))
= (($55.40 + 1.49BTC x $920) - ($0 + 1BTC x $900)) + (($500 + $0 x $920) - ($1,000 + $0 x $900)) // convert BTC to USD for the price at that time
= (($55.40 + $1,370.80) - ($0 + $900)) + (($500 + $0) - ($1,000 + $0))
= ($1,426.20 - $900) - $500 // My assets is worth $1426.20 at the end of the period, it was worth $900 at the beginning of the period but I added $500 from external sources (deposit - withdraw)
= $26.20 // Total value of my assets increased by $26.20


Even if I made zero trades for the month and the BTC price increased while I had BTC "stock", I would have made "profit" from a USD perspective as my total assets' value increased in USD terms.