Premise:
"The critics I spoke to, however, offered credible arguments."
Hypothesis: There were no arguments made.

no

Premise:
"As above, while several alternatives were considered, the SEC found that it was unnecessary or inappropriate to adopt any of them because of the need for investor protection."
Hypothesis: The SEC found it unnecessary or inappropriate to adopt them because of the need for investor protection, but the investors disagreed.

it is not possible to tell

Premise:
"yeah it's crowded i know that"
Hypothesis: I am aware that it is crowded.
yes