gap fills when there is bad news but so far, it's doing fine. Look at BLUE, it filled the gap after the expectation of their drug is lowered. Another reason a gap can fill is when the market tanks hard which put pressure on ZIOP but so far, a lot of buyers come in when it went below $8 these last several days.
The gap was the results of partnership with Anderson last year so it gapped up with good news.
As long as they continue to post good data, I don't think the gap will fill.
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