The Meg finished second this weekend to Crazy Rich Asians (other WB film), but it wasn't by much about $4 million and beat the other new releases Mile 22 and Alpha. The Meg is also outperforming the two other monster films released this year, Rampage was nearly $100 million worldwide less overall at this point (although it was outperforming expectations), and Pacific Rim: Uprising never reached this point (only hitting $290 million worldwide).
The Meg has also done very well in China, the second biggest market after the US, with $117.2 million there (already beating PRU there). With a budget of around $130 million (plus it's ad budget) it won't have to do a tremendous amount more to be profitable. While these numbers are estimates they shouldn't change much and we will update them once actuals are in.