I would expect to see appropriate use of $1B before dilution to yield $5B. One would hope that appropriate use of $1B as company approaches/commences commercialization would negate need for dilution, or at least allow stock sales at higher price/less dilution.
Just as most us would argue against buying or selling positions all at once, I would argue against that level of dilution at once. Would likely not be well received here or in the markets.