With a 24/7 hour market, you’d think forex would be profitable any day. In a way, it is—with a $4-trillion volume, there’s something to be gained any given minute. But timing is crucial, as any forex veteran will tell you. Just as there’s a good and bad time to ask your boss for a raise, there are good and bad days to trade. These are determined mainly be the amount of movement and change in the market; the more active the market is, the more you’re likely to gain from trading.

Generally, the best time to trade is the middle of the week, where the major players—banks, companies, governments—are in the thick of their activity. Companies import products, banks make loans and get deposits, governments sell treasury bills, and most importantly, amidst all this, currencies change hands. As soon as Friday noon rolls around, the market slows down. Of course, there are always exceptions—snap elections, bankruptcies, natural disasters—that come unannounced and spur the early weekenders into last-minute action. But you don’t want to jump in at major news events, as the market will be all over the place and there’s likely to be more guesswork than anything else.

Needless to say, weekends and holidays are the slowest days and therefore the worst times to trade. Popular events such as sports finals can also divert some of the traders from the market, although the effect isn’t as drastic. The market doesn’t stop completely on slow days, so it’s not an absolute rule—if you think there’s something to be gained, go for it!

For more precise timing, try to trade at an hour where two or more markets are in session. Depending on where you are, this can be at the start of a work day or smack in the middle of the night. If you plan on doing this long-term, it may help to have a market hours chart so you know when to sit down and get to business.

Of course, you can also go the DIY route and figure out the best times to trade on your own. The simplest way to do this is to look at the numbers and see when the pip spreads—the difference between the lowest and highest prices of a currency—are the largest. A wide pip spread means that there’s lots of exchange going on that causes a significant swing in prices. But whether you do your own analysis or use a cheat sheet, the rule is simple: always follow the action!