Investors confidence determines the value of product. Luna foundation has massively lost the confidence of its investors but will it ever be able to win it back, totally depends on the wisdom,capabilities and commitment of its management team to handle the crisis they are in. I believe Do know is a courageous & committed person.Though his experiment of pegging stable coin with basket of crypto currencies failed and failures are part of life but he should continue doing new experiments with improved and reliable risk management strategies.
There is no mathematically possible way for them to gain those investors back. Could they do something that would be a low cap stuff? Maybe. But they will never get back to where they used to be. This was a coin that was in the top 10 for a while, and now they are nearly fully gone and I do not see them ever coming back.
With UST dropping and depegged, they are spending all of their money to buy and burn and keep it at 1 dollar pegged, which is a difficult thing to do but they are not succeeding neither, so they will always be the project that failed, and why would anyone trust them to succeed when all they provided so far is failure and loss of money for investors?