This is the 13422nd most frequent Russian word.
накапливают
"Accumulate" or "collect."
In this sentence, 'накапливают' refers to the gradual gathering or accumulation of knowledge over time.
Они накапливают знания годами.
They accumulate knowledge over the years.
Here, 'накапливают' describes the regular addition or accrual of interest on investments.
Инвестиции накапливают проценты каждый месяц.
Investments accumulate interest every month.
In this context, 'накапливаем' indicates the continuous process of gathering resources needed for a large endeavor.