Why did my call option lose money when the stock went up?
Because a call's price is more than a bet on the stock going up. It also pays for time (which shrinks every day) and for the swing the prices expect (implied volatility, which often falls after news such as earnings). If the stock rose less than those two took away, the call lost money. And the price you can actually sell at (the bid) sits below the middle price, which takes a little more.
Try it: a call on a $50 stock, strike $50, 30 days left, priced at 60% implied volatility (a made-up level, high, as options can be just before a company reports). Move the stock, let days pass, let the volatility fall.
Simulated example, priced by the StrikePath engine (Black–Scholes, interest 4.3% a year). For learning; not advice.
The three forces on a call's price
The stock's move. Up helps a call, down hurts it, by roughly the call's delta (about half a dollar per dollar for a call at the stock's price).
Time. Part of every option's price is time value: what you pay for what might still happen before expiry. It shrinks every day, and, for an option near the stock's price, faster near the end.
Implied volatility. The price also carries the size of move the market expects. Before a known event it is often high; once the news is out it often falls back (traders call it the volatility crush), and the option's price falls with it.
The rise you actually needed
To come out ahead, the stock has to rise enough to pay for the time and the volatility you bought. For a call held to expiry that is the strike plus what you paid: the call in the example above, bought for $3.51, needs the stock above $53.51 at expiry. Before expiry, the answer depends on how much time and volatility are left, which is what the demonstration above shows.
What this shows, and what it doesn't
It shows how a call can lose value while the stock rises. It can't tell you what happened to your own option. To look at a real loss, compare the same contract at two moments: the stock's price, the days left, the implied volatility, and the bid and ask (a last-traded price can be stale). The split above depends on the order the changes are applied, because they interact; together they always add up to the total.
What the price already assumed
An option's price can be turned around to show the move it assumes. StrikePath's free earnings check does this for an option you type in: the move the price assumes through the report, and where you break even if volatility falls back the morning after.