There are many reasons why your basement would have cracks developing. It’s most common to find hairline cracks about one month after construction finishes and then into the first year, foundation cracks will likely begin to appear.
These are typical and mean very little – if anything – to the structural integrity of the building. There can however be some problems with water leakage. Sealing basement cracks is about preventing water damage that can compromise the construction so it’s always wise to address them before they allow this damage to occur.