Detailed account information in unsealed envelopes

Very rarely have I ever received mail that is in unsealed envelopes. So when my investment financial institution sent two, I started to worry. The financial institution that I have my Roth IRA with sent two account statements, complete with my name, address, balances, and account numbers in them completely unsealed. I considered that perhaps someone had opened them, but they did not show any indications of tampering. In fact, they don't look like they've been sealed at all. I can understand one envelope may have been left open, but two? And it just happens to be one where most of my money is?

How unnerving. Does this happen often to anyone else?