Trading Pair Advice from the Platform
So BTCUSD is a trading pair
in trading you always exchange something (BTC) for something (USD)
the last part is the advice from the platform what you could do with the specific pair. (in this case sell the first for the second)
this is my guess because we do not know the context really, some forcast software/apps are also integrated with the ability to exchange directly if you open an account with them)
As for my interpretation (assuming it is only forecast):
If you have BTC they advice you to sell BTC for USD because the market will be favourable this way (you will profit form this trade in the future because they expect the USD to be valued higher than BTC).
If you have LTC they advice you to sell LTC for BTC because the market will be favourable this way (you will profit form this trade in the future because they expect the BTC to be valued higher than LTC)
Do your own research about what could happen in the future, forecasts are forecasts and nothing more, don't come crying because you lost money by trusted a forecast. They may be factually based, but they can still be completely wrong. You may lose everything, many people have and will.