A day after General Motors(GM) - Get Report won the battle against activist investor David Einhorn and Greenlight Capital, Deutsche Bank's Rod Lache says there's another threat to the manufacturing giant.

Lache says that although shareholders rejected Einhorn's bid to split into two share classes, GM remains the cheapest stock in the S&P 500, Barron's reports.

On top of that, Lache notes GM might not be done with activists eyeing potential for asset spin off. GM's undervalued growth assets might mean there's room for larger market cap companies such as Tesla(TSLA) - Get Report or Mobileye (MBLY) within GM.

This is problematic, Lache writes, because there aren't many growth investors looking to spend on smaller subsidiaries GM already owns, such as OnStar. When these "Auto 2.0" opportunities must compete with highly valued competitors for capital, GM's entities might not fare well.

GM traded up over 1% in early afternoon trading.

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