Yes and no.

I'm going to backpedal (a little bit).

It will take the FDIC looking through all of their books to determine everything that happened - with bank implosions like this there were probably people on the take who knew what was happening. I suspect that more than one person will go to prison for financial fraud.

Take a look at this -

https://www.macrotrends.net/stocks/charts/SIVB/svb-financial...

So total assets of the bank doubled over a two year time period. That's bad. In the financial world having too much money is (typically) a big no-no, because it means that you have to invest that money in worse and worse performing assets (in this case assets with a worse risk profile). That's why a large number of successful small cap VC and hedge fund operations don't scale.

It also means that in this case the firm had most of it's cash from institutional investors (so they weren't FDIC insured) - which makes them more liable to bank runs.

I will agree with you that it looks like the firm primarily had a mismatch of ten year security treasury bills versus their responsibilities to clients. However, this is a symptom of the same problem - the bank, most especially since it was servicing mostly institutional clients - should not have been so overly sensitive to a single financial instrument. There should have been dollar cost averaging of buying securities over smaller time frames, as well as buying a mix of US treasuries with shorter maturities.

There also should have been, and this seems obvious in retrospect, a mixed basket of international treasuries and other assets to counter the risk profile of institutional investors that are primarily in the technology space. If technology stocks mirror the broader US economy but with higher volatility, then there should have been other assets held that would be counter cyclical to technology firms, such as a mixed basket of industrial stocks and commodities.

So I will say that you're right in that they weren't making riskier loans so much as they weren't diversifying their portfolio given the size of their asset base. Given that these were large sized institutional investors as opposed to FDIC insured clients, not investing in a mixed basket of asset classes is not good.

You're effectively paying for the lower rate of return that a treasury bill has because it's insured against risk, without being able to take advantage of that insurance. This is true in a roundabout way - given that the Federal government has to bail out banks during a financial crisis their return to the investor reflects that risk (not only in absolute terms but in the way the yield tracks the overall economy). Most banks should stick to treasuries because they don't service institutional clients and so can take advantage of that insurance. That wasn't the case here.

It doesn't look like diversifying their portfolio would even be possible given how fast their assets increased. I suspect that they started absorbing a large amount of crypto money because people didn't know where to put it and there should be some investigation into whether other banks are diversified enough.

It looks like possibly corrupt banking leadership and probably ignorant clientele. The intelligence of people is often inversely proportional to how fast they can make money for nothing.

In short, massive increases in assets is a huge red flag.

Here's a Barron's article on the subject which has some more numbers -

https://archive.ph/r2vEk